herf 373 days ago [-]
f.lux author here, still slogging through the article. It is hard to understand the light levels used because they use "power" (uW, mW) from a laser, and not "irradiance" (uW/cm^2 or mW/cm^2), so which area they have concentrated that light over is hard to understand. All I can see is it is from a laser, so the irradiance could be extremely high.

The human lens filters most light at the peak of the given spectrum for free retinal (383nm), and so once you get to 450nm like an LED, the hazard data in the visual range is 100x less sensitive, see Fig 1 here:


It bears repeating that computer screens have <5% the hazard-weighted irradiance of a blue sky. (Can't make a direct comparison with lasers.)

Not sure the conversion to white light is correct, and it is unclear to me right now if this much retinal is available in vivo.

wpasc 373 days ago [-]
Thank you for your input, but I mostly want to thank you for f.lux. It has been one of my favorite things for a long time. It's silly how long it's taken companies to provide a native blue light filter and your product just kicks ass.

If you guys ever wanted to figure out your app on a smart TV (or apple TV), I know there'd be a lot of thankful people!

Also, I'd love to contribute to the ongoing dev of f.lux (I don't think I've had to pay for it?) How might I?

Vesther 373 days ago [-]
Check out the FAQ for a PayPal donation link:


Huge thanks to the author from me as well!

wpasc 373 days ago [-]
Thanks for telling me :) Paypalling now
guru4consulting 373 days ago [-]
thanks for the link. I have been using flux for years and recommending it to my friends too.. just donated a small amount..
robrichard 373 days ago [-]
On the AppleTV go to Settings > General > Accessibility > Display Accommodations > Light Sensitivity.

Then you can assign it to the Accessibility Shortcut and turn it on or off by triple pressing the Menu button.

CardenB 373 days ago [-]
Can't wait to do this tonight! This will help so much
sundvor 373 days ago [-]
Hook your TV up to a computer running f.lux or similar! I've used a HTPC for the past decade and more, wouldn't go back.
tough_luck 373 days ago [-]
For my Samsung TV I use movie mode and also change colour temperature to warm.
rapnie 373 days ago [-]
I have the "blue light filter" on by default, on my android mobile. Don't know how effective it is, but it will at least help a bit.
exhilaration 373 days ago [-]
On my Google Pixel, this is under Settings > Display > Night Light.
daveFNbuck 373 days ago [-]
In Android Pie, it's also one of the 9 shortcuts you get when you pull down from the top twice on your home screen, right next to airplane mode.
copperx 373 days ago [-]
I just want to remind everyone that LED backlights emit blue light that isn't eliminated by f.lux or similar utilities.
herf 373 days ago [-]
You might want to refer to our measurement project for some numbers:


Also, you can be below threshold for circadian responses just by being very dim.

hohenheim 373 days ago [-]
Looking at your measurement, if I understand it correctly, you are saying that OP is incorrect and flux does in fact reduce the blue light?
mediaman 373 days ago [-]
Can you explain this more? If LED backlights emit multispectrum light (to get a white), and the LCD display filters those spectrum via RGB selection (say, letting less blue through, and more red/green), wouldn't this effectively filter the blue spectrum?

I know very little about this so I'm genuinely curious.

372 days ago [-]
abledon 373 days ago [-]
So if a new macbook pro has:

"15.4-inch (diagonal) LED-backlit display with IPS technology; 2880-by-1800 native resolution at 220 pixels per inch with support for millions of colours"

What possible laptop alternatives are out there that are better for eyes?

herf 373 days ago [-]
If you are curious, the smallest doses where "blue light hazard" has been observed in humans (short-term exposure) are around 10 J/cm^2. International standards use around 2 J/cm^2 for a safety margin.

One example of this is hiking in fresh snow for hours, no sunglasses, meaning exposures well above 10,000 cd/m2 to "white light".

Computer screens are way dimmer - an hour of iPad use is .0365 J/cm^2.

http://www.nature.com/eye/journal/v30/n2/full/eye2015261a.ht... is a good summary.

For long-term exposure (AMD risk) we have very little data, so understanding the mechanisms (such as above article does) can help.

phyzome 372 days ago [-]
Do those numbers account for pupil dilation?
taneq 373 days ago [-]
Hijacking this for a moment to say thanks for f.lux :) I've been running it for years and it's one of those things where you don't really notice the effect until you turn it off and then EGADS MY EYES.
erikbye 373 days ago [-]
Windows 10 has this built-in, so does macOS.
arama471 373 days ago [-]
I assume you mean the night light button in the action center?

If so I would argue f.lux does a lot more. For one thing you can choose the hue it goes to, but also unlike the Windows 10 one which (AFAIK) is simply on/off, f.lux will adjust based on a schedule which means that you don't typically notice the effects (as the change happens slowly). This, combined with the ability to change damn near every parameter it uses, makes f.lux significantly better.

Edit: apparently windows does have hue adjustment and sunset/sunrise activation/deactivation available. TIL.

erikbye 373 days ago [-]
Both macOS and Windows 10 has on/off now, scheduling, less/more warm adjustment. Windows 10 even has sunset to sunrise based on location.

EDIT: HN is becoming more like Reddit every day, I see. Ridiculous. Down-voted for pointing out the existence of helpful features. EDIT: might have been my fault.

wuliwong 373 days ago [-]
Probably you were down-voted because of you starting with "What you are saying is wrong." People probably didn't like your tone and the original comment was only somewhat inaccurate. There still are more features in f.lux than the built in options.

And I assume you understand that since you edited that line out.

erikbye 373 days ago [-]
Correct. I realized that opening line set the wrong tone and was unnecessary.
solarkraft 373 days ago [-]
I know these features exist in some places. But nobody had it before f.lux. And it's still - imo - one of the best implementations.
bvy 373 days ago [-]
f.lux screwed up how my MBP displayed graphics so I'm just using the built-in tool now. Unfortunate.
mi100hael 373 days ago [-]
IIRC that's a bug in the Intel graphics driver or something. I ran into that in the past as well and it's not directly f.lux's fault.
slothtrop 373 days ago [-]
There was nothing wrong with your tone.
saagarjha 373 days ago [-]
Night Shift on iOS and macOS also has a sunset-to-sunrise setting.
ycombinete 373 days ago [-]
You'll almost certainly get down-voted on HN for whining about being down-voted, and for comparing it to Reddit.
373 days ago [-]
mk89 373 days ago [-]
Just checked. Also Mac OSX has Sunset to Sunrise based on location.
visualstudio 373 days ago [-]
I've been a flux user for years, but sadly I had to switch to the Windows 10's version. Flux causes a 1 frame lag every 60 frames which was driving me crazy. Only fix was to put it into Safe Mode, but Flux is really janky in that mode; especially when alt tabbing. The Windows 10 version also has no lag while shift colors. It's a shame. I'd love to have kept supporting flux.
herf 373 days ago [-]
Our 2010 version polled once a second to get around a lot of bugs (Intel GPUs back then would forget their color settings on standby and lots of other things).

Since our update last year (v4) f.lux stopped doing this and does a lot of other tricks to reduce impact on framerates too.

no_identd 372 days ago [-]
Too bad neither f.lux nor the Windows 10 version properly support color profiles. f.lux has some support, but it sucks. And the Windows 10 version just outright has NONE. :\
benrbray 373 days ago [-]
These are relatively new features, and they arguably wouldn't have been added if not for the popularity of flux ;)
erikbye 373 days ago [-]
Does that matter? It's built-in now, and that's why I commented. To raise awareness. If built-in features have you covered there is no point going third-party.
jakemauer 373 days ago [-]
I understand where you're coming from but they don't have feature parity. Flux allows me to target much lower color temperatures than MacOS' built in "Night Shift" feature. That alone makes Flux worthwhile.
rootusrootus 373 days ago [-]
Does it take a long time to get used to that? For me, Night Shift at full warm makes some websites difficult to use due to the change in color. I can't imagine going even warmer.
epmaybe 373 days ago [-]
out of curiosity, how low are you going in terms of temperature?
bradknowles 373 days ago [-]
It's nice that they are there for people who won't install 3rd party software to get the extra features, but f.lux is still better.
opan 372 days ago [-]
I would argue that if some software is under a free (libre) license, it's worth using over [non-free] first party stuff. This doesn't apply to f.lux, but does to redshift.
oh_sigh 373 days ago [-]
I would argue that it is only because of f.lux(and it popularizing the blue=bad idea) that MS/Apple/Google put this ability in their products. The technical ability to do such a thing has existed for ...decades, but no one ever did it until after f.lux came out.
cmurf 373 days ago [-]
So does Fedora, courtesy of recent versions of GNOME with "Night Light" feature.
davidy123 373 days ago [-]
Ubuntu got that too with the switch to Gnome. Before that, I used the open source https://github.com/jonls/redshift
chasote 373 days ago [-]
ChromeOS has this feature for chromebooks now as well under the experimental flags section in case those users miss f.lux too. You can go to chrome://flags and search for Night Light to enable. As others have mentioned, I would rather use f.lux but (and my memory is hazy on this) I think the f.lux creator said the ChromeOS folks were not providing something he needed to get it working right.
wpasc 373 days ago [-]
I wonder from whom they took the idea? f.lux has been around for YEARS (2009)
ackfoo 373 days ago [-]
Also, this was done on cell lines in vitro, only one of which was derived from a non-diseased human retinal epithelium (ARPE-19). Cell lines have undergone genetic change that allows them to replicate indefinitely, so they are fundamentally different from normal cells.

I presume that they used a laser because they anticipated that it would potentially take years to see a result from a non-coherent blue light source, far exceeding their available funding, patience, and ability to keep uncontaminated cell cultures going.

Applying a blue laser with unknown irradiance to a retinal cell line from a single human genetic source in vitro is very, very far from proving a link between blue light and diseases such as macular degeneration and RP.

All this demonstrates is that coherent blue light is capable, under certain circumstances, of interacting with retinal to produce cell damage.

Any relationship to human disease on the basis of this paper is pure speculation. Advising people to wear "blue blocker" sunglasses or avoid cellphone screens (or take Vitamin E!) is pure fantasy made up by the scientific press to sell your retinas.

refurb 373 days ago [-]
Great analysis of the paper’s experimental protocol.

Isn’t the other “sniff test” that we haven’t seen a huge increase in age related retinal diseases since the introduction of computer monitor and handheld devices?

If these sources had such a big impact, it would be obvious from incidence numbers.

ALee 371 days ago [-]
The problem with this is that the desktop computer being widely used is probably the late 1990s (and we should be isolating for screens that emitted the white light/blue light mentioned. Assuming that it takes daily exposure over a number of years say 20 years, we should probably start seeing that within the next 5-10 years from tech industry workers. It may be as severe as tobacco or as benign as fluoride, we'll see early indications, but we won't know until much later. I think everyone just likes it when it feels better for your eyes to filter out blue light.
fouc 373 days ago [-]
I wanted to leave a note for others to keep in mind that f.lux can make the computer screen TOO comfortable to read in the evening. Which can lead to eye strain.

I used f.lux for 2 years. I found that I would stay up way past my bedtime, glued to the computer screen, and end up with correspondingly tired & fucked up eyes.

So I got rid of f.lux, and after that, I would go to bed at a more proper time. When the screen starts irritating my eyes, it's a direct indication that it's time to close the computer and get the hell to sleep. Ever since that, my eyes have done a lot better, because I no longer push to stay up way past my bed time.

opan 372 days ago [-]
I also tend to have eye strain if I'm computing very late at night, and take it as a signal to go to bed. I've described this to people, and it seems it doesn't affect everyone. It could also just be that there's a difference in awake time, blink frequency, or some other factor. I'll often go to bed more because my eyes are giving up on me and starting to burn rather than any sort of mental fatigue. I don't always keep normal daylight hours, so read this more as staying awake a long time than something specific to daylight
fouc 371 days ago [-]
The pain signals of eye strain doesn't seem to hit right away, so I can keep reading past the point where I really should stop. The pain creeps up gradually but it's really too subtle if I'm stuck on an engaging story. But I don't have that problem if I turn off f.lux, that way my discomfort is more immediate and I stop.
nnain 370 days ago [-]
What you described is exactly how I've been feeling for last 3-4 years. The pain signal kicks in the next day, sometimes even a day after. So yeah you can't tell at the time you're working late how the eyes will feel the next days. Sometimes it also triggers a headache and that spoils the whole day.

So the only solution I have figured is to be regimented about my screen time. I love working late at night and now have to tell myself to turn the work off. That kinda sucks.

Btw, It happened both with my previous laptop with LCD screens and the current LED screen.

For a few months I got hooked to Mobile gaming, and that just multiplied the problem! So I drastically cut down on my mobile time and that helps. My mobile had an LCD screen btw; so LED or LCD doesn't seem to be a factor for this particular problem.

fouc 370 days ago [-]
I also ended up getting prescription glasses (really mild correction) to reduce eye strain when staring at computer screens. I only wear the glasses when looking at computer or phone (ideally, but not always).

I also found retina display helped reduce eye strain.

jensvdh 373 days ago [-]
I suffer from chronic photophobia thanks to Uveitis. Flux allowed me to keep my job.
Forge36 373 days ago [-]
I'm running f.lux on my work PC (tones down a bad otherwise VERY bright-blue monitor).

Thank you for reading/writing out your interpretation of the article so clearly (highlighting points others are likely to trip on not coming from a related background)

hinkley 373 days ago [-]
Have we fixed the “optimized for electronics store demo” problem with monitors yet?

Part of my ritual of setting up a new monitor is to turn down the brightness and increase the contrast. They almost always default to very bad values. Brightness, temperature and green/blur balance are all off for an office setting.

In the worst case the backlight was capable of outputting twice as much light as I really needed.

userbinator 373 days ago [-]
When I got my first LCD monitor, the first thing I did was turn the brightness down to 0 and the contrast to slightly above; at that point it was already plenty bright enough, and after a few years when I noticed the brightness begin to fade I increased it 2-3 notches.

I suspect part of it is also planned obolescence --- when the backlight is running at full brightness, its lifespan is greatly decreased. Now the aforementioned monitor is approaching 15 years of age and brightness has reached 20/100, so there's still plenty of life left in it.

Moru 373 days ago [-]
Leds often dim faster when young. Something else will most likely fail before the leds are too dim. On the other hand flickering can be more obvious if you lower brightness of a led. Brightness is usually emulated by turning the led on and off very fast.
LeoPanthera 373 days ago [-]
Most/all modern monitors have presets, one of which is "store demo". All you've got to do is pick the calibrated preset.
no_identd 372 days ago [-]
Hey since I have you here, please, can you add support for proper color calibration, profiling & characterization to f.lux? Or at least outline in more detail how f.lux handles color profiles?

I wouldn't mind having to create multiple display profiles for this, but right now, flux seems to only support non-LUT based, Matrix based calibrations and only if they have VCGT headers, and then only based on those headers.

But this seems highly problematic.

Take a look at this page here for why:


I assume you based the current mechanics of f.lux when it comes to handling color profiles based on what the quickgamma homepage says about this:


To quote:


Apple has been using the LUT since many years for its operating system built in color management. In fact, Apple has registered the private ICC Profile tag video card gamma table (vcgt) with the International Color Consortium (ICC). This tag is used in a dedicated Monitor Profile and holds the gamma values, which are then loaded into the LUT by a loader program.

Hardware based Monitor Calibration Systems also use the vcgt tag, which in this case contains the correction data to achieve the monitor calibration. Because Windows did not provide a LUT loader, each calibration program had to provide its own LUT loader program. ...


Things changed when Windows 7 came along and provided its built in calibration loader, which not only loads the LUT at system start up, but also takes care of Standby and Hibernate.


As you might notice, the two stories from those pages seem to conflict?

Right now, when I use Windows to load my icc profile, I get correct colors. Same if I use the DisplayCAL profile loader.

However, if I start f.lux during the day (where f.lux shouldn't mess with the colors at all) I get semi-incorrect colors - they end up "more correct" than when I have no color profile loaded at all, but still VERY incorrect.

jonhendry18 372 days ago [-]
Surely you don't expect color profiles to work when f.lux is operating? I'm not sure what the point would be for color profiles when you're explicitly opting for distorted color reproduction with f.lux.

Is what you want more like "don't mess with the operation of color profiles when f.lux is disabled or otherwise shouldn't be adjusting the screen?"

no_identd 364 days ago [-]
>Surely you don't expect color profiles to work when f.lux is operating?

1. Don't call me Shirley.

2. I in fact do, in a way:

>I'm not sure what the point would be for color profiles when you're explicitly opting for distorted color reproduction with f.lux.

I opt for __linear distortion__ of a non-linear function. What f.lux ought to do consists of shifting the whitepoint coordinates of the current color profile. Which has the point of only distorting colors in a way where my brain can adapt to it.

But that's not exactly what f.lux does - it already DOES try to account for color profiles, but it does so incorrectly.

henvic 373 days ago [-]
Hi herf, your software is really nice but one thing that kept me from using it (and adopted since Apple's 'night shift', though I don't use all days) is that I enjoy photography. Probably you heard this a few times, but one thing that I'd love to have is this off for photos (I'd switch from being an eventual user to being a full-time user).
Moru 373 days ago [-]
I do color sensitive work now and then too. All you need to do is right-click the icon and select "disable while running [active program]".

I was very happy when I found f.lux. Finally something replacing my own tool I wrote for my Atari.

The main benefits with f.lux is you can easily set brightness and on/off with keys in any program or game, no need to navigate with mouse in menus.

372 days ago [-]
rakotinci 373 days ago [-]
You can just disable it for an hour. That's what I do at least.
ALee 371 days ago [-]
Herf - it would be great if you guys could have an official position on this paper and to really help us understand what flux is doing or not doing. I tend to see you folks as the vanguard pushing the bigger tech companies to adopt your technology - I for one tell EVERYONE to download Flux.
akashaggarwal7 373 days ago [-]
Ever since f.lux came into my life, my long screen starring hours have stopped causing me headaches and bad sleep. My phone and my computer have night mode on, all the time! Thank you for f.lux!
spaceandshit 373 days ago [-]
I'd like to thank you as well. I jailbroke my iPhone just to get flux on there (before Night Shift), and still prefer it over Night Shift.
abledon 373 days ago [-]
how does eye color factor into this? I read that objects with certain colors reflect rays of the same wavelength.
sizzle 373 days ago [-]
Thank you for many years of f.lux. How would you say it stacks up against Nightshift in iOS and macOS natively?
zengid 373 days ago [-]
f.lux is amazing; thanks for your work!
mafuyu 373 days ago [-]
I'm in the process of building a Philips Hue-compatible light therapy LED strip that goes above my bed, and I chose 500 nm cyan LEDs due to this concern. The goal is to have the lights gradually wake me up every morning and help align my sleep cycles, as I suffer from Delayed Phase Sleep Disorder.

Figure 3[0] in the paper seems to show that 500 nm is safe, and that melanopsin has high absorption at 500nm, which has important effects on circadian rhythm[1].

Anyone more knowledgable than me know if this setup is safe?

[0]: https://www.nature.com/articles/s41598-018-28254-8/figures/3 [1]: https://en.wikipedia.org/wiki/Melanopsin#Effects_on_circadia...

herf 373 days ago [-]
Yes, also if your eyes are closed when it starts, 500nm is better because more gets through the eyelid. Better if you diffuse more and spread out the light over more of the visual field.

But the main thing you'll want to make sure is that you can get enough light. There is some evidence that >200 lux with this wavelength will help, but most light therapy uses tons of light (1500 melanopic lux or more):


mafuyu 373 days ago [-]
Thanks for the tips! That link is super interesting.

I'm guessing melanopic lux is the lux output weighted over the spectral absorption curve of your eyes?

Some napkin math: I have ten 3W LEDs, and each might produce around 1000 lux when fully driven. If we drive each at half strength, and half of the generated lux is melanopic lux, that's 2500 melanopic lux.

herf 373 days ago [-]
Yes, lux depends on the viewing distance. Lumens is related to total light in all directions, and lux is "per area" (i.e. gets smaller with 1/distance^2).

Melanopic is weighted by the non-visual response in the eye, and this number corresponds pretty closely to the spectrum that drives circadian effects, and likely, mood. So whereas an incandescent might be 0.45 melanopic lux per visual lux, a really blue sky (or a 500nm LED) is around 2.0 "M/P".

priccis 373 days ago [-]
I'm sorry I can't help you, but after reading an article posted here about melatonin I got interested in light therapy, but commercial devices are a bit expensive. Are you documenting your project?
mafuyu 373 days ago [-]
Sure, it's not the most exciting project, but I might do a short writeup when I'm done.

I originally purchased these nice LED strip bars with enclosure in blue[0], but after reading this site by the manufacturers of a commercial green therapy light[1], I was convinced to switch to turquoise/cyan.

Turquoise isn't that popular so I wasn't able to find any strips/bars, and I got these individual 3W bead LED modules instead.[2]

For the Hue integration, I'm using a Mesh Bee + UartSBee v5[3] with firmware from PeeVeeOne[4]. It outputs PWM, and I'm hooking it up to a cheapo constant current LED driver I got from Aliexpress. Since all the LEDs need to be in series for a constant current driver, I'm probably looking at a ~20V power supply to power the whole thing.

My bedframe has a headboard, so I'm planning on 3D printing some mounts that clamp on top.

[0]: https://www.ebay.com/itm/50CM-U-Aluminium-shell-DC-12V-36-SM...

[1]: http://www.sunnexbiotech.com/blue%20vs%20green%20light.html

[2]: https://www.aliexpress.com/item/10-pcs-3W-Turquoise-Cyan-LED...

[3a]: https://www.seeedstudio.com/Mesh-Bee-Open-Source-Zigbee-Pro-...

[3b]: https://www.seeedstudio.com/UartSBee-V5-p-1752.html

[4]: https://peeveeone.com/?page_id=252

bb88 373 days ago [-]
So those cyan LED's have a forward voltage drop of 3.2-3.6 volts. So you'd be looking at a 32V-36V 350ma power supply or thereabouts to hook them up in series.

If it were me, I'd probably run everything in parallel just to keep the voltages lower, and be able to use readily available power adapters.

Aliexpress has a PWM controlled constant current driver that takes 5-35V in and outputs 350ma max [1]. 10 of them are $20, so they're not too expensive.

At a forward voltage of 3.3V for the LED's, you'd be looking at slightly more than 1W per LED at 350ma (P = VI).

Those constant current supplies probably have an efficiency of maybe 66%, taking that into consideration, I would think a 12V 2A power supply would be enough to drive the entire thing. And that could be a wall wart that you get at the local hardware store.

[1] https://www.aliexpress.com/store/product/10PCS-A58B-1W-LED-D...

mafuyu 373 days ago [-]
Just tested with my power supply, and the minimum V_on seems to be about 2.7V. So if I want to drive all 10 in series, I'll need 30V+. If I had three banks in a 4,3,3 configuration, I could get away with a 12V power supply as well, which would be nice since I already have a bunch of 12V 5A wall warts.

I already got the board you linked, supposedly configured for 700 mA. Haven't tested yet. The datasheet for the part says it can go up to 2A[0], so I could potentially modify the feedback circuit for 1A, which would reach the full 3W rating of the LEDs.

One issue with that driver chip is that the PWM/enable is active low, so I think I may just stick an inverter on the output of the Mesh Bee. The SDK for the NXP part has changed since the ZLL repo was updated, and I haven't had much luck getting it to compile myself.

[0]: http://www.xlsemi.com/datasheet/XL4001%20datasheet.pdf

therein 373 days ago [-]
Why do you want to drive the 10 LEDs in series?
bb88 373 days ago [-]
So note the I/V curve on the diode [3]. The minimum on at 2.7V is probably going to be the "knee" voltage. Sending 1A through the led will be a higher voltage.

The easiest way to test it is to get a multimeter, and put 1A through the led, then measure the voltage across the diode, and that will be the voltage you're targeting. (or you can just use one of the 700ma current regulators for a good estimate, placing the enable to ground.)

Also keep in mind that those current regulators are buck converters and they're not 100% efficient (no regulator is, really). So you're going to want to add 20-30% more power at a minimum on top of the load you're planning on driving with it.

And if you're going to drive 12V of LED's, expect to need 15-18V to drive the buck converter. That's because of the way buck converters work.

The feedback voltage on that chip is a fixed 1.2V and that's used as an internal voltage reference (I guess because they didn't add one into the chip).

They have a circuit diagram for that part, and it looks like CS and Rcs are the most important things on that sheet. CS is the "Current Sense" that measures the voltage across the current sense resistor (Rcs). They give the formula for Calculating Rcs to get to 1A (ILED = 0.155 / Rcs), and I get .15 ohm for Rcs at 1A.

Then you can either replace it with another sense resistor with something like this [2], or an appropriate length of copper wire [1] to give you the correct resistance.

As far as the PWM/enable inversion goes, just invert it in software. 100% full duty cycle would be off and 0% would be on. If you have a Raspberry PI laying around you can easily set one of the pins to PWM to test out your inverter code [4].

I'm going down a similar path to build a UV light box for exposing PCB's and the like.

Best of luck!

[1] http://hyperphysics.phy-astr.gsu.edu/hbase/Tables/wirega.htm...

[2] https://www.mouser.com/ProductDetail/Bourns/CRM2512-FX-R150E...

[3] https://www.electronics-tutorials.ws/blog/i-v-characteristic...

[4] https://circuitdigest.com/microcontroller-projects/raspberry...

fpgaminer 373 days ago [-]
You're a hero; thank you for posting details.
justinc8687 373 days ago [-]
I would be very interested to see a write up of what you are doing here as I have a similar problem. Any chance you could share one if you create one? Email in my profile.
mafuyu 373 days ago [-]
Yep, will do!
mark-r 373 days ago [-]
Do you have a spectral output chart for those LEDs? You might be surprised how much blue is still in the output.
mafuyu 373 days ago [-]
Yeah, especially with these cheapo Chinese LEDs. I looked into spectrometers, but they seem pretty pricey. Maybe some sort of plastic filter that blocks the shorter wavelengths?
bb88 373 days ago [-]
How about a simple prism? That would tell you instantly if there's any blue light in the stream.

Edit: You might need a mask to create a slit of light so you can see the spectrum clearly.

mafuyu 373 days ago [-]
Oh, yeah! Totally forgot about those from high school chemistry class. :)

I'm sure there'll be _some_ blue light. I don't know if a prism would be high resolution enough to tell if it's a dangerous level.

bb88 373 days ago [-]
Yeah, you won't be able to see the intensity, but you will be able to see what components of the spectrum are there. It's also and easy way to test filters.
chrisper 373 days ago [-]
Any reason why you are not just buying a Philips wake up light? I have one and it's great. Especially during darker months
mafuyu 373 days ago [-]
I wanted something that was compatible with my existing Hue system, and specifically targeted wavelengths for light therapy.

I already have a normal Hue bulb next to my bed on a schedule, similar to the wake up light, but a light strip right above my head seems more appealing to me.

sc00ty 373 days ago [-]
How long have you been using yours? I have been using one for about 3 years. Initially it worked great, but it seems the light just doesn't do it anymore and the alarm sounds are what eventually wake me up.
chrisper 373 days ago [-]
About a year. But I am having similar experiences.
thewizardofaus 373 days ago [-]
Perhaps try and cycle using the light. Couple months using it, one month off etc.
lewisinc 373 days ago [-]
I remember having serious issues when I was younger with this. It's still sort of a a problem, but I've learned to cope. I'd also be interested if you documented your setup :).
otuutti 370 days ago [-]
Got my kitchen lighting done with these hue controlled light strips. Not entirely certain if they fulfill your need, but maybe an alternative if someone wants to replicate. They have very good CRI, which might be good/bad for your application. https://www.sowilodesign.com
GekkePrutser 373 days ago [-]
Wow that's totally what I have too. I didn't think there was a name for it.

I mean the delayed phase sleep disorder. Will talk to the doc about it.

373 days ago [-]
negadave 373 days ago [-]
I work with reef aquariums and we use something similar for our reef tanks at the store to wake up the corals
rgrove 373 days ago [-]
> To protect your eyes from blue light, Karunarathne advises to [...] avoid looking at your cell phones or tablets in the dark.

Can someone explain why it would be worse to look at a cell phone in the dark? It's emitting the same blue light (or less, if the display gets dimmer) as it is in a bright environment. Why is that light more harmful in a dark environment?

kjullien 373 days ago [-]
Because of the way your eyes work. If it is bright, your pupil will be shrunk, to not be blinded by the luminosity. When it is dark, your pupil will be opened wide up.

It is this principle that camera apertures are based on.

Now if you have your pupil wide open in a completely dark environment and put a 100% brightness screen at ~10cm of your eyes, what do you expect will happen ? Our eyes are made for nature, that means day and night, now we have technology that is akin to a handheld sun and you use this at night at 10cm of your face, our eyes are simply not equipped to handle this.

dsr_ 373 days ago [-]
... but I don't put a 100% brightness screen in front of my eyes at night. Do people really do that? Don't they know how to adjust brightness?

Indoors, I use about 30% brightness. As the day gets dimmer, that slides down to about 25%. If I'm reading something in bed, I start at about 10% and as my eyes adapt, go down to 1%. When I'm finding it hard to keep my eyes open, I take that as my signal to go to sleep. Am I ridiculously unusual?

anonytrary 373 days ago [-]
This isn't weird at all. I'm jealous of your 1%. The default low on my phone is maybe like 5-10% (I don't know how to check this), and it feels crazy bright when I'm in bed.
mohn 373 days ago [-]
If you're on Android, I recommend Screen Filter[1] which will draw a semi transparent overlay on top of nearly everything (depending on the phone and/or OS version, it might not dim the status bar, bottom navigation buttons, lock screen, etc.). I use it a lot when reading at night, because the lowest brightness setting on my phone is also too bright for dark-adapted eyes.

[1] https://play.google.com/store/apps/details?id=com.haxor

andymal 373 days ago [-]
Shades is also a good app on android for dimming the whole screen much darker than the default slider will go.
anonytrary 373 days ago [-]
Wow, thanks a lot. Just tried it out and I'm loving it so far. I really appreciate the default reversion in case the slider is set too low, as well as the non-linear percentage slider allowing for fine-grained control at lower brightness values.
oceliker 373 days ago [-]
For iPhones you can set a full screen “zoom” with low light filter on. It’s under Settings -> General -> Accessibility -> Zoom. Set the filter to Low Light, then turn on zoom, then double tap with three fingers to zoom out all the way.
saagarjha 373 days ago [-]
What phone are you using?
JoshCole 373 days ago [-]
It can be beneficial to suppose a perfectly spherical cow.

You aren't unusual for trying to prevent your eyes from being harmed. If you were, an article which helps inform on the topic of eye care would not be popular.

373 days ago [-]
lucb1e 373 days ago [-]
I do for videos because I notice that I just see a lot more. Turning down the brightness is like turning down the light in the room that was filmed in. That's both on OLED and on LCD screens (wish I could go back to OLED, though, but it has gotten fairly rare among cheaper phones).
wingerlang 373 days ago [-]
Some people do it, yes. My girlfriend used to have her phone at 100%. Personally I use f.lux and the lowest setting.
rconti 373 days ago [-]
Interesting; when I got 2 new pair of eyeglasses last month, again I fell for the usual "buy all the coatings" spiel. I didn't much understand what they were, but I was told one causes refractions that bother some people.

I absolutely notice a blue refraction from car headlights when driving at night. I keep thinking I'm seeing a police light from somewhere. It's fine, just interesting. Well, after looking at a few lens coating websites, and realizing my lenses reflect blue light back at me if I have a light source to reflect, they're obviously blocking blue light -- cool!

I've never been much for f.lux style color shifting, I HATE the obviously inaccurate colors. I also wonder if we'll find that some of these technologies don't work nearly as well as a blue filter, and that perhaps the light just LOOKS less blue.

But I'm sure glad to have glasses that now block some blue light. Also, it validates my desire to keep the blinds open at work; I have LOTS of light coming into my cubicle area. Sometimes it's even a bit annoying but keeping my pupils small should help.

klodolph 373 days ago [-]
What makes f.lux inaccurate? Color perception is relative and if you are in a dark room, your eyes should adjust to different white points naturally. This is the same thing that makes it so a white piece of paper looks white no matter whether you are inside or outside, even though the actual light reflected from the paper has a radically different spectrum in each case.
rconti 373 days ago [-]
shrug. Same way the 'average' person does. Looks totally wrong. I notice it from the first minute it starts to shift. I notice it every time I look at the display of a coworker who uses it. I tried it for a few months thinking it would cue me to go home, at least, but I just started snoozing it the instant it began sunsetting -- forget the more extreme ends of the progression.

I never work in a perfectly dark room. My office is next to a window, both at home, and at work. The lights are on. Plus, all of these things help keep my pupils small which apparently helps prevent the blue light harm to begin with.

foo101 373 days ago [-]
The colors on a RGB-based display is incorrect either way (with flux or without flux) at any color temperature (cool, warm, or in between).

Why is it that you prefer the incorrect colors without flux to the incorrect colors with flux?

Sounds like you prefer cool color temperature which is no more correct than warm color temperature.

driverdan 373 days ago [-]
I'm not OP but I can't stand f.lux and its clones. I never adjust. The inaccurate colors stand out to me no matter what the conditions are.
klodolph 373 days ago [-]
"Inaccurate" is definitely an incorrect way to describe the colors. The colors are correct from relative colorimetric perspective, you're just changing the white point.
eggie 373 days ago [-]
Any 3-color screen will never be true to life accurate. It's always a simulation of the real thing projected into the three dimensions of color that most of us perceive.

Colors appear to change dramatically under different lighting conditions, but we accept these changes as normal given context. Changing the white balance on your screen is no different. It's not inaccurate, it's just rendered as if in different lighting conditions.

dlkinney 373 days ago [-]
Just because "white" can be recognized as "white" under varying color temperatures doesn't mean that the spectrum isn't truncated, and thus less accurate.

We have the ability to adapt to different color temperatures and perceive the relative output, but we're still missing information when shifted from the full spectrum daylight we evolved with.

Consider a recorded rock song: if we gradually apply a low pass filter of increasing strength, the high frequencies will be cut. We'll still be able to hear and recognize the cymbals, for example, but the stronger the filter, the less accurate the output.

Just because we can recognize relative colors under different lighting conditions, it doesn't mean that they're still accurate when we remove information.

darkerside 373 days ago [-]
> perhaps the light just LOOKS less blue.

That is a really interesting distinction! Blue is a color derived by social consensus, but it is also a particular wavelength of photons. I'm curious about what's there if we dive in and examine what specific wavelengths of light (numerically) cause damage, and what is the overlap with what we typically consider the color blue. I'm sure it's not one to one.

skybrian 373 days ago [-]
We're able to see similar colors under different lighting conditions only because the mind adjusts what you see for lighting. Seems like the same should be true for filters.
jt2190 373 days ago [-]
> I absolutely notice a blue refraction from car headlights when driving at night.

I think some ultra-bright headlights are actually slightly blue.

mrguyorama 373 days ago [-]
Especially with the move to LED headlights, car lights have gotten significantly "colder" in color temperature
rconti 373 days ago [-]
nah, it's a refraction in the lens -- eg, i see it offset from the actual light source.
Brakenshire 373 days ago [-]
Isn't blue light important in the mornings for keeping the circadian rhythm aligned? I thought you were supposed to avoid it in the evenings only. Probably it'd be fine for you if you're getting a lot of light, but might be bad if you don't.
373 days ago [-]
rgrove 373 days ago [-]
Hmm. If I've been in the dark for a while and then pick up my phone, the brightness hurts my eyes for a moment until they adjust to it. When I put the phone down, it takes a moment before I begin to be able to see things in the dark room. Doesn't that indicate that my pupils were initially dilated in the darkness and then constricted when I began looking at my bright phone?

I wonder how significant the difference is between pupil dilation while looking at a bright phone in a dark room and while looking at a bright phone in a bright room.

asdkhadsj 373 days ago [-]
If it is the delay in dilation that causes the damage, I imagine it's exacerbated by constantly changing dilation as well. Ie, if I'm staring at my phone in the dark, I rarely keep focus on it. I often glance to the left or w/e, thus causing the screen to appear too bright again. Same for laptop-ing in the dark. I often find myself looking at keys, or thinking off in the distance, or w/e.
lphnull 373 days ago [-]
serious question: Why do people like to do work or leisure in pitch black rooms? Don't you feel clumsy, sleepy and uncomfortable when everything is dark? How can anybody go more than 10 minutes without needing to use vision to interact with their surrounding environment?

I personally can't have the lights off even if I'm watching a movie. Maybe because I was raised without TV, I can't sit still for more than 20 minutes watching entertainment before I feel the urge to do something productive like wasting time on the internet.

asdkhadsj 373 days ago [-]
> serious question: Why do people like to do work or leisure in pitch black rooms?

I prefer low light, not pitch black. Generally speaking I want my monitor to be the main focus. Same for TV; if I care about the viewing experience I dim the lights. I might even prefer pitch black honestly, but due to the reasons being discussed, the contrast is just too great.

> Don't you feel clumsy, sleepy and uncomfortable when everything is dark?


> How can anybody go more than 10 minutes without needing to use vision to interact with their surrounding environment?

Not sure, tbh. I imagine it has to do with not wanting to interact with the environment most of the time. Ie, what am I going to do with my banister? It's just sitting there.. why do I need to interact with it? Most of my house is the same way. If I'm doing X, rarely do I need to interact with the rest of the house or room.

Does it bother you that there are things behind your head that you can't see?

Diti 373 days ago [-]
Very personal answer to your serious question (sorry if it isn’t relevant for others): I can’t stand the stimulus caused by light (one of the problems that come with being part of the autistic spectrum). I wear sunglasses at work (because of the bright fluorescent lights above). Being able to work in the dark is a relief.
lphnull 373 days ago [-]
It's funny that I'm reading this thread because I just went through this exact same thing last night and it was weird. I don't ever make a habit of using my phone in the dark, but I did yesterday and I did at full brightness and for many hours and it did not feel good.

Eventually after like 6 hours in the dark and accidentally using just one eye for reading- eventually I started to see really trippy and weird visual noise in the dark areas of the room. I also noticed that if shone at the right angle- the pitch black areas of the room suddenly lit up, as though I was giving my over-exposed eye some kind of night vision, which is weird because you'd expect an oversaturated eye to be completely blind in the darkness.

Now this is all anecdotal, but reading screens in pitch black light has always felt bad for me. I don't understand people who insist on watching TV shows or movies in a fully pitch black room. I mean I get why school teachers and home theater enthusiasts do it- but for normal TV viewing, it just seems wrong to me.

coldtea 373 days ago [-]
>Doesn't that indicate that my pupils were initially dilated in the darkness and then constricted when I began looking at my bright phone?

Somewhat constricted. They're still more open that if they were in a fully lit environment, even more so in the sun.

FPGAhacker 373 days ago [-]
get some IR leds and illuminate your face and take a selfie in the dark looking at your phone using the front camera.

The back camera usually has an IR blocking filter, but often the front camera does not. You can check by videoing an IR led (like from a remote control) with the front camera and seeing if you can pick up the flashing when you activate it.

athenot 373 days ago [-]
The same happens with computer screens. Most offices are under-lit (or over-lit but only if ALL your UI has a dark background).

To get a feel for this, point your cell phone at your desk area and take a picture (without HDR enabled). If you can't take a picture without over– or under–exposing the screen or the wall, then your setup is putting strain on the eyes.

foolrush 373 days ago [-]
This is absolute quackery.

Your camera's cell phone barely manages to hold approximately eight stops of latitude. Blowing out that pathetic dynamic range has no grounding in relation to any notion of "eye strain".

athenot 373 days ago [-]
> Your camera's cell phone barely manages to hold approximately eight stops of latitude

That's precisely what makes it a decent tool for detecting lighting imbalance. Just because our eyes mask the issue with high perceptual dynamic doesn't mean it's not straining them.

foolrush 373 days ago [-]
Eight. Stops. Is. Not. High.
rndmwlk 373 days ago [-]
That only happens for, what, less than a second before your eye adjusts? It's not like your eye knows it's day or night, and the pupil stays fixed.
Ntrails 373 days ago [-]
My phone (unlike my PC, or a TV) is smart, and thus dynamically alters brightness based on ambient light. It's pretty cool and certainly mitigaets the above somewhat
rory096 373 days ago [-]
At least on my phone (LG G5), the lowest brightness setting is still incredibly bright in an otherwise dark room. I use Twilight[0] to dim it further, though unfortunately Google changed Android so it can't affect the soft buttons. (Which is fine for almost all apps because the soft button bar is black, but of course Chrome changes it to white with no way to fix it.)

[0] https://twilight.urbandroid.org

verall 373 days ago [-]
I recommend, instead of Twilight, to use Lux[0]. It has many settings and lets you completely set your own brightness curve, with "negative" brightnesses that darken your screen with an overlay included. Also lets you adjust color temp, of course. The free version had all the features I needed.

[0] https://play.google.com/store/apps/details?id=com.vitocassis...

mywacaday 373 days ago [-]
Thanks for prompting me to go back and check the settings on the Darker(https://play.google.com/store/apps/details?id=com.mlhg.scree...) looks like it now dims the soft navigation buttons
doh 373 days ago [-]
iOS is the same. Even on the warmest setting and lowest brightness it's still very bright. Unfortunately, there is no app to do anything about it like there is on Android.
Tyr42 373 days ago [-]
There is a setting, so I can tap three times with three fingers each time top open a menu and set a filter, and I choose low light mode

It's not the easiest mode to find, but works.

walterbell 373 days ago [-]
You can configure iOS Home button triple-click to invert the screen, so it's white text on a black background. There is a "Smart Invert" option so that photos are not affected.
r00fus 373 days ago [-]
You can also apply an accessibility filter to increase the darkness in iOS. I have this mapped to a triple home-button click and use it all the time (after reading to kids etc)


doh 373 days ago [-]
I'm on X so no more Home button, but good suggestion. For last 9 months I had my phone on grayscale, which was nice, but still a bit high for my taste.
graeme 373 days ago [-]
You can go further by reducing white point in accessibility settings. The colour filters there also go beyond night shift.
doh 373 days ago [-]
Interesting. I was on grayscale for last couple of months, but didn't know I can reduce the white point also. Will try.
stephengillie 373 days ago [-]
My TV, a Toshiba Regza, has dynamic brightness. It works very well as my primary monitor.
niceperson 373 days ago [-]
Would using a kindle at night have the same effect? It's light is kind of yellowish (I think)
jonhendry18 372 days ago [-]
Probably less so because it's reflected off the e-ink screen surface and probably diffused a bit that way.
niceperson 372 days ago [-]
Right. Also the illumination is at the bottom of the screen and hence indirect, whihc might reduce it further.
baq 373 days ago [-]
My first gen Paperwhite is most definitely blue, it's obvious at low brightness. Don't know about later models.
lawlessone 373 days ago [-]
I'm not a doctor but in a dark environment your pupils would be less constricted.

From what i heard this is also why sunglasses that don't block UV light are worse than not having sunglasses at all.

colanderman 373 days ago [-]
Your pupils are more dilated, due to the surrounding darkness, and hence let more light in. If you were to dim your screen enough to compensate, it would likely be too dark to read.
CapitalistCartr 373 days ago [-]
Your pupils are dilated; you're receiving more light.
373 days ago [-]
mikeleeorg 373 days ago [-]
For the f.lux Mac users here, do you prefer that to Mac's Night Shift?

I just found this article, which details why f.lux is better than Night Shift. But it's written by f.lux, so it's a bit biased.


I'm guessing both are better than nothing, but is one actually better than the other?

Eric_WVGG 373 days ago [-]
I've been using F.lux for over seven years. Advantages…

- You have a great deal of control over the blue level. Night Shift's blue level is higher than F.lux's default, and not adjustable.

- Flux transitions more naturally as the sun goes down.

- More scheduling options, "disable until tomorrow".

- the big one: disabling per-app or for full-screen apps. You probably don't want Flux on while watching a movie or binging on a videogame. (I set up my lady friend with Night Shift and watched a movie with her recently, spent the whole film wondering why they made such awful color choices)

shanev 373 days ago [-]
First point is incorrect. Night Shift's color temperature is adjustable, which includes the blue level.
applecrazy 373 days ago [-]
While the color temperature is adjustable, I've found (anecdotally) that the warmest setting on Night shift is still quite a bit more blue compared to the max warmness on F.lux.

(Tested on iMac and MacBook Air, may be different for other screens)

enos 373 days ago [-]
- Night Shift is disabled for external displays. That's another killer one.
xvector 373 days ago [-]
NightShift absolutely works on external displays
jamroom 373 days ago [-]
I use Night Shift on my external 4K LG monitor no problem.
beager 373 days ago [-]
I prefer f.lux, with the exception of fullscreen video, specifically YouTube on Chrome, where certain colors "break through" the filtering and appear bright white. Not sure how it works, but it's the only thing Night Shift seems to do better. If f.lux fixed it I'd be back in a heartbeat
sbjs 373 days ago [-]
I use Night Shift. I'm able to fall asleep minutes after closing my laptop and laying down. For me it's more about comfort than sleep. The blue light is much too bright late at night. My computer no longer hurts my eyes when I stay up late working on cool things.
saagarjha 373 days ago [-]
I use Night Shift because it’s built in and does what I want it to do without glitching.
JimboOmega 373 days ago [-]
I don't quite understand. Blue light - any blue light - causes blindness? So we shouldn't look at the sky even?

I've never heard blue being a danger other than its effect on the biological clock, so that seems like a pretty bold claim. Ultraviolet, sure...

Though buried in there is something about immune system and vitamin E levels...

I really find it hard to believe that blue light exposure is automatically bad. We have receptors for that specific purpose. Wearing blue light filtering sunglasses all the time as the article suggestions seems a bit ridiculous. Why give up one color entirely?

antt 373 days ago [-]
The first thing to realize about any scientific paper is that it's wrong. To a very good approximation all scientific papers are wrong, until the results are replicated a couple of dozen times and failed to be replicated a few times this could well be an artifact of the methods they used.

Never make life changed based on the results of one single study.

sp332 373 days ago [-]
It says that your body's normal antioxidants prevent damage. This is only a problem for people who have low levels of alpha tocopherol, e.g. from malnourishment or aging.
astrodust 373 days ago [-]
We have chemical receptors on our tongue and in our nose for poisons. We have neurons that detect pain. Just because we can sense it doesn't mean it's not harmful.
vosper 373 days ago [-]
But those receptors signal something unpleasant - a terrible taste, pain. Looking at blue doesn't cause pain or unpleasantness.
jcl 373 days ago [-]
I'd guess that the negative effects of blue light over a lifetime might only have become noticeable in modern times, with better vision correction and treatment for conditions like glaucoma and cataracts. If so, there probably hasn't been significant evolutionary pressure to dislike viewing blue light. Also, half of outdoors is blue half the time, so instinctual blue-avoidance would probably hurt survival.

But it is perhaps misleading to concentrate on things that are exclusively blue... The real problem is light containing the relevant range of frequencies, which includes many non-blue colors, due to the relative presence of other frequencies. For example, your eyes would probably absorb much fewer relevant photons when staring at an empty patch of sky than when staring at the sun, even though the sun is not considered blue. And looking at the sun does cause unpleasantness.

dqpb 373 days ago [-]
On the contrary in fact, I find gazing at the blue sky to be calming and enjoyable, and find it promotes diffuse thinking, which can greatly speed up problem solving.
coldtea 373 days ago [-]
It's not about merely seeing something blue, like the sky, in a generally warm temperature ambient light. It's about blue color from screens.
astrodust 373 days ago [-]
Some people like the smell of ozone.

Ozone doesn't have a smell. What you actually smell is your nose burning. Ozone is a very aggressive oxidizer.

Looking directly at the sun is also a super bad idea.

saagarjha 373 days ago [-]
> Ozone doesn't have a smell. What you actually smell is your nose burning. Ozone is a very aggressive oxidizer.

Wait, what? Do you have a source for this?

foo101 373 days ago [-]
> Ozone doesn't have a smell.

This does not sound right. This is what I see on Wikipedia which is also exactly what I was taught in high school:

> It is a pale blue gas with a distinctively pungent smell.

Source: https://en.wikipedia.org/wiki/Ozone

xvector 373 days ago [-]
I don't think your argument holds. Case in point: it is possible to make poison tasty.
jonhendry18 372 days ago [-]
Try gazing unprotected at a nearby arc welder flash.
manmal 373 days ago [-]
Just speculating here, but I‘d say since eyes have evolved to also look at the sky, I’d say no. Shining a laser on cells is different from sunlight in various ways. First, laser light waves are coherent (perfectly overlapping), so their effect might amplify A LOT. The dosage (J/cm) used by the researchers also might be 100x as high as the sun‘s, for all we know. Then, there’s the thing that sunlight is a mixture of a very broad range of frequencies, from far infrared (and below, microwaves etc) up to ultraviolet (and beyond, eg X-rays, which luckily don’t arrive at the earth surface in huge doses). Again, just speculating, but near infrared has been found to have a beneficial effect on retinal diseases, so maybe it compensates for the problems blue light creates.
jonhendry18 372 days ago [-]
"since eyes have evolved to also look at the sky"

On the other hand the Inuit had to invent snow goggles to prevent blindness caused by the bright sun reflected off the white snow-covered terrain. Like, actual eye damage blindness. That's been attributed to UV but perhaps blue wavelengths play a role as well.

IanSanders 373 days ago [-]
As others mentioned:

When you look at the sky during a bright day your pupils are narrow and let little portion of the light through. When you look at blue light in the dark - they are dilated and let more light through.

coldtea 373 days ago [-]
>I really find it hard to believe that blue light exposure is automatically bad.

Few things are "automatically" bad. Over time though, effects are cummulative, and there are also breaking points for lots of bad stuff.

JohnBerea 373 days ago [-]
In addition to f.lux, I also use the Dark Reader Chrome extension[1], which dynamically generates dark themes for every page you visit. It seems to make a bigger difference than using f.lux.

1. https://chrome.google.com/webstore/detail/dark-reader/eimadp...

adtac 373 days ago [-]
How does the amount of blue light we see from our computers and mobile devices compare to the blue light seen from the rest of the world quantitatively? While I agree that f.lux helps in the night, I'd guess that the impact caused by f.lux to prevent the effect mentioned in the article is pretty minimal. (Obviously, I have no citations or references; just a wild guess.)
kakuri 373 days ago [-]
Thanks for sharing! I did not know about this. I use Stylus and dark themes for many sites, but this will be great for random sites. https://add0n.com/stylus.html
verta 373 days ago [-]
Def'ly a great relief for my eye strain - using it during the day too and keeping on by default. One annoyance is that Chrome needs to let the address bar be darkened as well as it stands out like a neon tube when Dark Reader is on.
m_ke 373 days ago [-]
I just use a dark chrome theme with it to get around that issue.
eggie 373 days ago [-]
Using this on an OLED screen really makes it clear that the current standard of light backgrounds and dark text is only optimal with backlit LCD panels.
gregcrv 373 days ago [-]
"to wear sunglasses that can filter both UV and blue light"

But isn't this bad with other consequences? I thought the lack of blue/violet light was the cause of myopia? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5233810/

derefr 373 days ago [-]
You can't develop myopia or hyperopia after your eyes/skull/orbital muscles are done growing. So this suggestion probably applies only to adults.

Keep in mind that this is age-related macular degeneration. Your photoreceptor cells are protected by the α-tocopherol until "a person's 50s or 60s." You wouldn't need any prophylactic interventions until then.

graeme 373 days ago [-]
Interesting. My myopia worsened a bit from ages 22-27 or so. Does that mean my skull and muscles were changing still?
UlisesAC4 371 days ago [-]
Actually yes. Doctors have told me that I should wait til 25 to see If I am candidate to eye laser operation because that is the average age where people stop developing his muscle eyes.
niceperson 373 days ago [-]
>You can't develop myopia or hyperopia after your eyes/skull/orbital muscles are done growing. Do you have a source for that?

Would the inverse also be true?

derefr 373 days ago [-]
I don't know about a source—a medical textbook? Those conditions are explicitly caused by the eye being squished out of the "proper" shape for focusing light by the way the skull and extraocular muscles end up developing.

I suppose you could develop myopia later in life as a result of inflammation of the extraocular muscles (orbital myositis), but this would be 1. temporary, and 2. not treated as its own disease, but rather as a symptom.

ectospheno 373 days ago [-]
VSP basically owns TechShield Blue. Other manufacturers have competing products but they are all pretty horrible.

The cynic in me wonders if the researchers have any ties to VSP.

friedman23 373 days ago [-]
I use f.lux all day I don't know if I'm particularly sensitive or if it's all in my head but when I turn off f.lux, especially at night, to watch some movie or video I can physically feel my pupils dilate and it almost feels like my eyes go from being at rest to being strained.
danaos 373 days ago [-]
As a linux user, I have found that Redshift works better than f.lux. It's the first thing that I install on a new machine of mine.
paulcarroty 373 days ago [-]
Last year use default "Night Light" in GNOME. Very easy and can be enabled in one click like Wifi or BT.
degenerate 373 days ago [-]
Same - I have flux setup to be active during work hours (at work) and evening hours (at home) so it's filtering blue light on all my devices. When I accidentally close it or turn it off for a movie, I feel like a vampire in sunlight. I have such an easier time falling asleep thanks to flux.
xur17 373 days ago [-]
I use something similar to flux for my lightbulbs, and I've noticed the same thing when I disable it at night. My eyes are definitely strained.
asdkhadsj 373 days ago [-]
Care to link what you're using? It would be nice to modify my room to use changing color spectrum bulbs depending on the time of day.
xur17 373 days ago [-]
I'm using this [0] Home Assistant component. I also use a similar component to slowly turn my lights on in the morning instead of an alarm clock, which works really well.

[0] https://www.home-assistant.io/components/switch.flux/

thirdsun 373 days ago [-]
Before using f.lux fulltime I noticed that I sometimes got headaches after long days in front of displays, so I started using f.lux not only after sundown, but also during the day and it's very effective. There's no way I'm going back. Essential piece of software for me.
zachrip 373 days ago [-]
I was recently diagnosed with a condition called retinitis pigmentosa (it basically just destroys your retinas). It's part of a larger condition called usher syndrome (which caused my severe hearing loss at birth). I'm on heavy doses of vitamin a palmitate as well as some other vitamins. Another thing that I haven't done yet but will be doing shortly is blue light blocking glasses, especially since I sit in front of a computer all day. I also use f.lux and night shift on windows and mac respectively. I'm 22 and have lost a significant portion of my night and peripheral vision so I'm still just trying to figure this all out. Any tips are welcome.
gyc 373 days ago [-]
I'm in my late 30s and was recently diagnosed with retinitis pigmentosa too. I've started to use night shift/f.lux on my computers, and reading this article is also motivating me to update my glasses to one with blue light blocking.
ScottBurson 373 days ago [-]
My wife's brother has retinitis pigmentosa. He's 64 and has been blind for years. You definitely have my sympathies.

I don't have any advice except to learn Braille, which I'm sure is not very encouraging. I hope a cure is found soon.

nathan_long 373 days ago [-]
I am excited about LED lights for their efficiency, but keep seeing articles like this and don't understand the practical ramifications, like "what bulbs should I buy?"

I messaged Cree on Twitter, expecting a very corporate response, but they linked to some studies (which I haven't yet had time to explore.) FWIW - https://www.energy.gov/eere/ssl/street-lighting-blue-light-a... and https://www.lrc.rpi.edu/resources/newsroom/pr_story.asp?id=3... were the resources they suggested.

herf 373 days ago [-]
The message is: there is no more risk from LED than older sources, by the metrics we have now.

I would suggest that one problem is that LEDs don't "warm dim" (unless you get some special ones from Philips and a few others), and people tend to dim them less overall.

nathan_long 373 days ago [-]
What do you mean by "warm dim"?
herf 372 days ago [-]
An incandescent/halogen will go to warmer temperatures when dimmed. So it might start at 2800-3000K but be 2100-2200K at 1% brightness.
jonhendry18 372 days ago [-]
Perhaps you could look into buying red lampshades. The direct illumination of the LED would still be rather blue but the light passing through the shade would not.
pmoriarty 373 days ago [-]
"The researcher found that a molecule called alpha tocoferol, a Vitamin E derivative and a natural antioxidant in the eye and body, stops the cells from dying. However, as a person ages or the immune system is suppressed, people lose the ability to fight against the attack by retinal and blue light."

Does this mean that consuming alpha tocoferol can combat the toxic effect of blue light? If so, at what dosage?

georgeam 373 days ago [-]
One solution I use is a 1/8" thick sheet of amber transparent rigid plastic/acrylic. It is designed to cut UV, but it also cuts blue light. I bought a 2'x4' sheet from an online site (since ads are probably not permitted, I will not mention the name of the company), and they cut it to size specifications for me. Out of that I got filters for my 14", 15" and 17" laptops, and a 30" LED TV.

I find it easier on my eyes at night (both laptop and TV), and it has its place since the TV can't run f.lux and redshift.

sp332 373 days ago [-]
Recommendations of products are fine. Paid promotions or kickbacks are frowned on though.
upofadown 373 days ago [-]
Note that the lens of the eye yellows as you get older which significantly reduces the amount of blue light that reaches the retina. So much so that there is an idea floating around that older people don't get enough blue light to properly make the circadian stuff work and that teenagers get too much.
onnnon 373 days ago [-]
I wear computer glasses at all times when working, and highly recommend them. It greatly reduces eye strain, and filters blue light.

If anyone is looking for a good pair, I buy mine from Gunnar [0] (no affiliation).

[0] https://gunnar.com/

hestipod 373 days ago [-]
Tried these and some Uvex glasses that block 100% of blue light (Gunnars are very low % blocking relatively). Zero impact on my strain. I have seen many others state the same. It's obv there are many causes for strain, just wish I could figure mine out.
splittingTimes 373 days ago [-]
what about EagleEyes? Does anybody have experience with these?

Blue light blocking: https://www.eagleeyes.com/pages/blue-light-blocking

Computer sunglasses https://www.eagleeyes.com/pages/digital-eye-protection

holtalanm 373 days ago [-]
if you need prescription versions, you can get them at LensCrafters: https://www.lenscrafters.com/lc-us/blueiq-lenses

I use those and they work wonders.

gumby 373 days ago [-]
Many of the comments here are about displays, but what about the LEDs sold as replacement for incandescent and halogen bulbs?
Brakenshire 373 days ago [-]
I think, white LED bulbs do use a single wavelength blue LED, but they pass it through phosphors which transform it into a similar distribution of wavelength that you would find from an incandescent bulb, or sunlight. LED's are a lot better than fluorescent lighting, which does often have very dramatic peaks and gaps.

In theory, you can look at the CRI rating, but in fact CRI only uses a small number of wavelength probes for the test, so a rating of 100 doesn't necessarily mean a smooth spectrum, it could be the manufacturer has tuned wavelength peaks in order to game the test. There are better rating systems being developed, but they're not used by manufacturers or mandated by governments yet.

I actually think it might be the lightbulbs that change colour which could be problematic. I wouldn't be suprised if some of those did generate the colour just with single wavelength blue, green and red sources. Hopefully the better ones would have individual phosphors for each r/g/b source which produces a spectrum which when combined is reasonable.

I would be particularly careful about cheap/unbranded colour-variable lightbulbs. I doubt they've been through much or any consumer testing, it seems you can buy anything straight off the boat from China through domestic web stores these days.

mark-r 373 days ago [-]
Yes, white LEDs are based on blue LEDs with phosphors. But I don't think they convert all the blue light, so they're still heavy on the blue output. I'd need to see a reference to believe they have less peakiness in the spectrum than fluorescent lights.

CRI may not be the best rating for spectrum smoothness, but it's the only one we have for now. It's still hard to find bulbs that even bother to rate themselves.

Eochei5h 373 days ago [-]
Check the spec sheet of the bulbs, specifically the color temperature in kelvin. Ignore the "warm white" and similar marketing terms, they are too fuzzy.

A LED with low color temperature and high CRI should have pretty much the same spectrum as incandescent. If you want really low temperatures look for some retro filament style LED lights.


pistachiopro 373 days ago [-]
It's tricky, though, since most LED bulbs use a single wavelength of blue LEDs which get downshifted by phosphors, even in high CRI bulbs, you can have an unnaturally large spike in the blue (often around 450nm).
Brakenshire 373 days ago [-]
CRI unfortunately is not a good test, it still can produce very high ratings even when the spectrum is spiky.
namibj 373 days ago [-]
95+CRI is an indicator for mostly lack of spikes. Look at Yuji (yujiintl.com), they seem to be the only ones selling actual high-CRI LEDs with sane pricing (i.e., no ideological markup).
mapmap 373 days ago [-]
I'd like to try one of these out, but at $20 per bulb it's a a bit steep. Are you able to comment how they compare to the Feit Electric 90+ CRI bulbs sold at Costco for a few dollars a bulb?
b_b 373 days ago [-]
For many of us whose use of these blue-light emitting computer and phone screens is necessary, what can we do about it?
kjullien 373 days ago [-]
Use f.lux or an equivalent (most OS have their own implementation by now) that filters out the blue light at software/rendering level, it's not perfect but you do instantly feel the comfort it brings to your eyes. Been using f.lux for over 10 years and it also helps alot with going to sleep at night. When it's off your eyes/brain thinks that they are in daytime / broad daylight, when it's on I fall asleep 2 or 3 times faster than without.
shittyadmin 373 days ago [-]
The biggest problem I have with it is that everything looks so much worse that I just wind up turning it off all the time.

Is this so seriously a threat to vision that it's worth it? I don't have the sleeping issues with screens some people seem to report, so I wasn't really willing to commit to it over that.

Raphmedia 373 days ago [-]
> The biggest problem I have with it is that everything looks so much worse that I just wind up turning it off all the time.

Change the settings. What you should do is take a sheet of paper and put it next to your screen. Then match your screen's white to the sheet. It's only a bit less blue. There's no need to set everything dark orange.

shittyadmin 373 days ago [-]
Okay, but that's a trade-off, you're still getting a fair amount of blue light through in that case. How much less blue light do you want? What's optimal for minimizing eye damage if that's a significant risk?
Raphmedia 373 days ago [-]
You don't want to eliminate all blue from your life. Decreasing it is good enough. What's the point of making your computer screen red if the minute you step outside in the sun you lose any benefit?
rory096 373 days ago [-]
Make sure you change it to the "Slow: Natural Timing" transition speed so the shift is gradual. The faster speeds (which I believe are default) are jarring and too easy to notice.
piyh 373 days ago [-]
Also Alt + page up/down to adjust brightness without affecting colorshift.
swebs 373 days ago [-]
The benefit of software such as f.lux and Gnome Nightlight is that they turn themselves on at night and off in the morning. It seems like the OP wants to remove blue light at all times, in which case should be handled through your monitor settings. A software solution would be unnecessary.
373 days ago [-]
373 days ago [-]
burkemw3 373 days ago [-]
You can wear glasses that filter blue light.

The article mentions wearing them outside, but they work inside as well.

I wear them, and they provide other benefits for me as well (https://news.ycombinator.com/item?id=16529054#16531413)

gambiting 373 days ago [-]
So I used to have glasses with a blue blocker filter on them - I absolutely hated every second of wearing them. Literally everything appeared yellow through them - my screens, sheets of paper, even snow looked like it had been peed on - awful. I mean, it's certainly not surprising - they did block blue light after all. But I wore them for 3 months and then marched back to the optician to have them replaced with normal lenses. And the optician has promised that the effect would be very subtle and hardly noticeable in daily use - well, maybe I'm particularly sensitive to it, but the effect was very noticeable to me.
rconti 373 days ago [-]
My new eyeglasses have a coating that reflect blue light. They absolutely do NOT shift the color spectrum. You can't tell the coating is there. Perhaps it's newer or different tech. Look into it.
saltcured 373 days ago [-]
Are you talking about the coating opticians are pushing for "computer glasses" now in the US?

I have that, and while it is subtle, I definitely can tell it is there. It doesn't ruin general color perception, unlike many obviously yellow/brown lenses. But, it definitely alters the world to have a slight yellow tinge, a bit like you can get from the haze caused by a distant dust storm or wild fire.

It doesn't bother me, but I am aware of it. I actually prefer brown sunglasses and photochromatics because what is marketed as "gray" often looks sickly purple to me.

gambiting 373 days ago [-]
I just don't understand how that could possibly work - it doesn't matter if the glasses absorb or reflect blue light - as long as it doesn't reach your eyes, anything that is normally white will look yellow, as you're not seeing the blue component. You can't filter/reflect blue light and still see it.
JdeBP 373 days ago [-]
Colour perception is not that simple. The visual cortex compensates. It's the same sort of compensation that means that you see the same colours for objects under artificial lighting and in sunlight, even though spectral analysis will show them not to be.
rconti 373 days ago [-]
Yup. I don't know how else to explain it. Trust me, I'm very sensitive to color temperature changes. I have 4 pair of eyeglasses I rotate through every day. Only 2 of them have the latest anti-blue coating. You simply cannot see it. I don't know what product it is, but a good example description from Zeiss:


red75prime 373 days ago [-]
Judging by the relative light intensities of daylight and computer screen light, I would say it will be sufficient to close your eyes for 6 minutes when you are outside on a sunny day to offset 10 hours of computer use.

Maybe dark adaptation can change that, but I haven't found anything about that upon quick unprofessional examination of [0].

[0]: http://twin.sci-hub.tw/6979/4112e16f7195f7f33cd3e861c6345df0...

jtl999 373 days ago [-]
I've been wondering if GB-R LED backlit displays help? I haven't seen any reviews which compare the LED spectrum vs a standard white (blue)LED backlit display, but it might be something of interest.

Examples of a GB-R LED backlit display include the NEC PA302W, so they aren't common.

goda90 373 days ago [-]
Well at least a start is to use software like f.lux that reduces the blue levels on the screen. There are also over screen filters and yellow tinted glasses that can filter the blue light.
pishpash 373 days ago [-]
It sounds like one should use it permanently, and not just at night. But the real problem is the spectral composition of the synthetic white light on screens. Now I want fluorescent backlights back.
bcoates 373 days ago [-]
Is there any reason to think that narrowband blue is worse than broadband blue? It makes for poor CRI when used as a light source but if the display blue is near the peak sensitivity frequency for blue it should result in slightly less total power being delivered to the eye than an equivalent blackbody spectrum white light.
pishpash 373 days ago [-]
Maybe total power isn't what matters and peak sensitivity is also where peak damage is.
kardos 373 days ago [-]
Android has a blue light filter, I haven't turned it off yet.
adventured 373 days ago [-]
I turned it on recently, mostly just to experiment and see how annoying the difference would be. It was subtle enough that I just left the filter on.
sandGorgon 373 days ago [-]
Fedora/Gnome has had "Night Light" built into the OS by default. Big difference to eye strain with it !
pishpash 373 days ago [-]
This is not a permanent solution because simply shifting the color temperature has the side effect of generating melatonin and disrupting your circadian clock. You really need a daylight white spectrum and not concentrate all the blue-green energy in one blue spike.
Razengan 373 days ago [-]
iOS, macOS and Windows as well.
ScottBurson 373 days ago [-]
Really surprised there's no discussion here about the ubiquitousness of black-on-bright-white color schemes in apps (including this text box I'm typing into right now, though for the most part, HN uses a soft beige tint for its background; but it's still dark-on-light). It's really quite unnecessary. For code editing I have a light-on-dark Emacs color scheme, which is much easier on the eyes.

Yes, Macs have a setting to invert the color palette, but that's not useful to me — a lot of my windows are dark; I don't want them inverted, and it makes images unintelligible. What I really want is something that doesn't screw with images, but detects dark-on-light text and maps the colors in such a way as to preserve contrast and even hue.

asadkn 373 days ago [-]
For many of us with astigmatism, the trend to default to dark schemes would be quite troubling. They're painfully uncomfortable irrelevant of contrast. There's fuzzing and "halation".

It took me a long time to figure out the why. I love dark layouts in terms of aesthetics, but I cannot use them.

Without being biased, from what I have read so far, the research seems favorable for dark-on-light as long as proper room lighting is achieved and monitor brightness and contrast is adjusted for it. In poor light conditions, the inverse seems to be true.

While there's a reason for current defaults, everything should be optimized for and have options for both black and dark schemes.

ScottBurson 373 days ago [-]
Fair enough; I don't mind other people using whatever they prefer, as long as I have an option for light-on-dark.

I wonder, though, what the real problem is that you have with dark themes. It could be related to the combination of wide-gamut monitor blacklights and high-index plastic eyeglass lenses. I wrote something about this here: http://scottlburson2.blogspot.com/2016/01/lcd-backlights-and...

hvidgaard 373 days ago [-]
I'm curious to why it's a problem. I have a astigmatism, but with glasses I have better than 20/20 vision and have zero issue with light-on-dark. Without glasses light-on-dark and dark-on-light alike are a problem to read.
jonhendry18 372 days ago [-]
I've had problems with light-on-dark text since my eyes started going bad at 40 (presbyopia).

Making the text several sizes larger than usual helps a bit. (Like, 20 point instead of 14.)

DavideNL 373 days ago [-]
Is this the same blue light as emitted by for example the Philips light therapy lamps?


jefe_ 373 days ago [-]
I use one of these every day, found two things, one from Philips in 2011 with some PDF documents, making claims the light is safe: http://www.p4c.philips.com/cgi-bin/cpindex.pl?ctn=HF3332/60&...

2011 was a while ago, this Stack Exchange post from 2013 seems to indicate there is a possibility for macular degeneration with use of these devices, particularly if you are already at risk for the condition: https://skeptics.stackexchange.com/questions/13891/can-blue-...

Some googling seems to indicate there were rumors of these lights potentially causing issues, and it sounds like the Chemist article may be presenting a scientific basis for that speculation.

Turned off my light for now.

squarefoot 373 days ago [-]
I deeply hate blue leds, never liked them. As an electronics hobbyist I have been used for many years to the old red then green and yellow leds before the blue and later white ones came out, so I rushed out to buy some as soon as I could and while trying them I remember feeling uncomfortable staring at that light, to the point I never used them in anything: they're staying in their box for good. I already know about the blue light altering the circadian rhythm, but didn't back then, so it's possible the brain was sending a message there was something wrong with that light.
lukewrites 373 days ago [-]
Can anyone recommend editor color schemes that look good when f.lux is set to heavily filter blue light?
ninkendo 373 days ago [-]
I’ve really started to like gruvbox lately. It’s naturally a warm color theme already so I would imagine it should still look good under a heavy blue light filter.
codemac 373 days ago [-]
Anyone have suggestions for kindles? A lot of the "screens" I've seen on amazon have pretty terrible reviews.

It's the one major source of nighttime blue light that I consume. I've largely given up using my phone / laptop in the dark, as I decided I'm an adult and can just leave the lights on.

Reading in bed is one of my favorite things, and it bothers my partner to leave the lights on.

smileysteve 373 days ago [-]
The contrast of just your screen and focusing in the dark is likely damaging on its own; but you can add the red filter, and, if using kindle app, make the font white on black background.

But yes, as Kindles imply, reading text printed without a backlight is preferable to backlit text, so prefer lights over the backlight.

graeme 373 days ago [-]
What about a red light in a lamp? I use a red light to read at night. Doesn't bother my girlfriend (though she's not hugely bothered by light in general)

Combine that with an e ink non backlit kindle and you'll have no blue light.

scns 373 days ago [-]
Yellow glasses block blue light
paulkon 373 days ago [-]

I've been using it for some time now.

By default I look at my phone, tablet and computer monitor in inverted mode. Video content is watched as normal.

Makes it way easier to get work done and keep the eye strain to a minimum.

titzer 373 days ago [-]
Green on black terminals. I actually miss them! Just sayin'
bradknowles 373 days ago [-]
Amber. Amber on black.
oblib 373 days ago [-]
I bought a monitor a couple years ago that has a "Low Blue Light" feature you can turn on/off.

At first I didn't like it. It kind of dulls the screen down and makes things look greener. But after using it for a couple months, along with a couple other monitors on my desk, my eyes were getting tired so I turned the feature on and used it for a few days to see if I could get used to it.

When I switched it back off afterwards I was pretty shocked at how much more my eyes were instantly stressed. I turned it back on and have left it on since. I also turned the blue down on my other two monitors. And I can feel the difference when I set them back to their defaults too.

I don't think I'd like it for TV, though I might get used to it as well, but for coding and surfing the web it works for me.

kjullien 373 days ago [-]
Did we not already know about this ? I remember 5+ years ago blue LEDs were pulled off of the market (at least in France) because the spectrum they emit in is way too close to uv and could burn your macula.
kypro 373 days ago [-]
Wait, is UV light bad for your eyes? Should I be careful about visiting bars with UV light too?
btrettel 373 days ago [-]
When I did research as an undergraduate, one of the MS students in the lab I was working in moved a powerful UV light used to cure glues from the corner of the room to the center and used it without putting a box over it as was standard procedure. Of course, he didn't look at the light himself, but he also didn't announce its use either. I saw the UV light as I was walking through the lab. It was basically a bright purple/blue light. Several hours later I was effectively blind due to pain, which continued for a few days. I basically had the equivalent of a bad sunburn on my eyes.

This was one of several reasons I quit that lab. Since then I've avoided academic labs that have UV lights or lasers because I don't trust that the students follow safety procedures at all.

MisterTea 373 days ago [-]
Supposedly the intensity of a "black light", the UV emitting lamps found in clubs/bars/amusement attractions/etc are below the harmful threshold.

I have never been comfortable in their presence as my eyes begin to fatigue and I experience discomfort. YMMV.

kjullien 373 days ago [-]
Yes, UV rays cause damage to pretty much any organic matter, that's the reason we wear sunscreen, sunglasses, and why cheap "fake" sunglasses can be harmful for your eyes (the glass is simply tinted and does not filter out the UVs, which is what they should be doing)

edit: the way I remember it is that like any type of radiation, anything that goes into your body stays there pretty much until your death, the only way to keep your "uv capital" in good shape is to be proactive about it, cant do anything retroactively. This is why about 1/3rd of Australians will develop some form of skin cancer in their lifetime.

gomox 373 days ago [-]
I just wanted to point out that most cheap (and therefore plastic) sunglasses are actually perfectly fine in terms of UV protection. Polycarbonate is UV opaque.

If you Google this subject there are several websites where people went out and bought cheap an expensive sunglasses and had them tested and reached the same conclusion: UV protection does not justify expensive Raybans.

avgDev 373 days ago [-]
Black lights used in clubs generally don't have enough power to cause eye damage or sun burn, therefore, I would not be too concerned.

Lights used in something like a tanning bed, can obviously burn your skin and also damage your eyes that is why people should wear eye protection, or do the healthy thing and not tan at all.

373 days ago [-]
lechiffre10 373 days ago [-]
On a similar note, has anyone heard of Felix Gray? I've been thinking of getting a pair of lenses from them. They make lenses that filter blue light and they happen to look pretty good too.
chroem- 373 days ago [-]
It's more than a little amusing to see this at the top of HN only a few days after getting attacked for posting my personal experience with blue light and retinal degeneration.
alain_gilbert 373 days ago [-]
You should post the link. It could be fun to compare the comments !
Rotdhizon 373 days ago [-]
Can someone say if it is harmful to use a blue light filtering software 24/7? I get its use at night, but would using it from sun up to sun down cause any problems?
graeme 373 days ago [-]
Only if you never went outside. Otherwise, it shouldn't. Blue light emitting screens are recent, if blue light is off, it's still more light than a book.

But never going outside would mess with circadian rhythm.

beams_of_light 373 days ago [-]
I wish I had never been privy to this information. All it's going to do is make me paranoid about yet another thing in life.
programUrJerb 373 days ago [-]
>Karunarathne introduced retinal molecules to other cell types in the body, such as cancer cells, heart cells and neurons. When exposed to blue light, these cell types died as a result of the combination with retinal. Blue light alone or retinal without blue light had no effect on cells.

Does anyone disagree that this is equivalent to looking at a phone?

upofadown 373 days ago [-]
It is already known that you can damage retinal tissue with the light from blue LEDs. At a particular power density blue will be the more damaging colour as it has the highest energy. So the question is if the intensities and duration of exposure encountered in day to day life can cause permanent damage to the retina.
ChikkaChiChi 373 days ago [-]
Don't want any blue light from your devices at night?

- AMOLED Android device with a custom kernel that supports color profiles set to fire only the red pixels.

- Get transparent red film from Amazon and cover your Kindle screen.

- Wear orange safety glasses at night to dramatically reduce all blue light.

- Bonus difficulty: Wear red laser goggles. Do not attempt to drive!

arprocter 373 days ago [-]
I wonder if the brightness settings have any bearing on this?

If I don't dial mine way down it's very uncomfortable

foo101 373 days ago [-]
What would be the right daytime setting in f.lux to reduce the harmful effects of blue light?

The default daytime setting under recommended colors in f.lux is 6500K. I tend to use a daytime setting of 5500K. Is 5500K good enough to reduce the harmful effects of blue light or do I need to go even lower?

corpMaverick 373 days ago [-]
From the article...

   To protect your eyes from blue light, Karunarathne advises

   to wear sunglasses that can filter both UV and blue light 

   outside and avoid looking at your cell phones or tablets in the dark."
Please share any additional actionable advice.
cheschire 373 days ago [-]
Set your monitor to R=49, G=34, B=19
lawlessone 373 days ago [-]
Wear Sunscreen

Start a pension.

downrightmike 373 days ago [-]
Go back in time and plant a tree.
fierybanana 373 days ago [-]
wodenokoto 373 days ago [-]
I don't know if this is a stupid question, but if I set my LED lightbulb to warm-light, or set my OLED phone to blue light filter / warm light, am I still exposing myself to this dangerous blue light?
pishpash 373 days ago [-]
I definitely feel I've been going blind, more than I should with age.
dewiz 373 days ago [-]
Now I’m wondering about the damage of all those Windows crashes and blue screens :-)

Seriously though, the sky is blue, the sea is blue, how come we’ve evolved into beings affected by blue light??

vladus2000 373 days ago [-]
This is affecting people in their 50s+, a lot of our evolution people had and raised offspring before this occurred so there was no evolutionary pressure to keep your vision much past that. It was good enough.
perilunar 373 days ago [-]
Yeah, but they're only blue during the day!
foolrush 373 days ago [-]
One would have thought that the thousands upon thousands of hours of daylight exposure would have already made us all blind if this was actually solid research.
peterclary 373 days ago [-]
Something to consider for VR headset manufacturers and VR software developers? Pumping bright blue light into the eye at close range seems like the worst case.
exegete 373 days ago [-]
Do we know why bankers chose green instead of yellow for their eye shades? I know they wore them due to eye strain, but why green and not something else?
fpgaminer 373 days ago [-]
Lots of comments here about blue-less lighting at night, so I thought I'd share my experiences in trying to warm-ify our household lighting. I'm in no way an expert; just sharing some experience.

It all started when we moved in to our current place. The previous tenants had left a bunch of old incandescent bulbs. I guess I had forgotten in the past two decades just how warm colored those lights are. It is a really comforting color temperature and great for getting sleepy before bedtime. Of course when I went to replace them with LEDs the contrast was obvious.

Now enlightened (heh) to the differences I went on a quest for warm colored LEDs. Turns out, that's really difficult. First I bought just any old light with the word "warm". But most LEDs you find are actually "warm white" or "soft white". Basically 2700K and up. Whereas old school incan. is ~2400K. The difference is huge and I was very disappointed.

So I began to filter my searches looking for things in the 2400K range. The local lighting store had _nothing_ (a store completely dedicated to selling lights). Amazon had a few options, but not many. Once you filter by low temperature and dimmable you begin to scrape the bottom of the barrel. Most were off-brand, which I try to avoid since poor quality LEDs will fail early when their cheap power supplies burn out.

I went through a few rounds of orders but finally settled on a set of Philips dimmable A15 lights "with warm glow effect". They are small enough to fit in all fixtures I've run into for those kinds of bulbs. But the best feature is that they change temperature as you dim them. So you have the option of a cooler "soft white" (2700K) at full brightness, or all the way down to 2200K when dimmed! To a non-expert in lighting they subjectively looked the best and gave us the same warm, comforting glow we were looking for at night.

So my advice, if you're looking to upgrade your house to warm bulbs, make sure to look for something 2400K or less.

Others have mentioned checking CRI, and that's important. I don't know the CRI on the bulbs I got. Again, they subjectively looked the best. But there aren't a lot of options in the truly warm color range so it's a feature I had to not care much about.

I also found some really great vintage filament style LED bulbs for a project (vintage style outdoor string lights with corded wiring; built from scratch). They're from a company I found on Amazon called Cmyk. Off brand, but they're the best option I found in that category and their packaging was actually really professional. They are labelled as 2200K, but they look even warmer than that. When dimmed about half way you get just the right amount of glow that you can see the faux-filaments. Super happy with those.

Beyond that you can also just get color-changing bulbs like Philips Hue. Since all this went down I've been slowly upgrading to those instead. That gives you the option to choose really any temperature you want at any point. I'm not sure how the "quality" of light from that setup compares to a real warm LED lightbulb. Obviously you're getting a "warm" color by mixing red and green LEDs so it isn't a true color temperature. But on the other hand you're definitely not getting blue light, which is the important thing. Either way, subjectively they look great and I wouldn't be able to tell the difference. (Usual caveats about buying into a somewhat closed system applies; Philips Hues are sort of the best worst option today.)

graeme 373 days ago [-]
What about morning wakeup lights? I have one that's daylight spectrum with 93 CRI. Is this generally ok, or harmful?
heed 373 days ago [-]
I wear glasses with a blue light filter coating. I'm not sure how much this helps though. Anyone know?
sunseb 373 days ago [-]
So I have switched my coding theme from "Cobalt" to "Solarized Light"
polskibus 373 days ago [-]
So LED bulbs would be even worse, right? Is it time to go back to incandescent bulb?
davidcyp 373 days ago [-]
google "blue light mrsa"

Blue light kills cells. It's used in hospitals to kill germs and also use to treat acne. Hand dryers also use them. I'm not surprised it kills certain human cells as well.

hestipod 373 days ago [-]
This or something connected to it is literally ruining my last chance at life but I cannot solve it and there is always a catch. I was disabled long ago by bad surgery and left in lots of pain. My physical career was ended. I was denied social assistance and fell in every crack. Life has never been stable enough long enough to reeducate and rebuild. In suicidal desperation I posted in a few places asking for ideas. A few months back a very kind person reached out to me in response to one of my posts on social topics and offered me an opportunity, a once in a lifetime thing that can work around my issues. In the process of updating my equipment (I had been primarily using a 12yo TN/CCFL having laptop) I experienced severe eyestrain. That sent me down a path of "why" and months later I still have no answer.

Eye doctor said I was ok and found nothing to explain this. I have monovision from Lasik done 20 years ago but it's never been an issue. I tested for and ruled out, to the best of my limited ability, the common gremlins like excesive blue light (always used f.lux/redshift before) and even tried the Uvex glasses that block ALL blue light. Tried PWM free displays and no change. Lowered brightness, changed ergonomics, font rendering, drivers, filters, OLED, ambient lighting. Anything common sense or the internet has come up with doesn't work for me. I even considered it was psychosomatic given the importance of me being able to do the one last thing I could do for any conceivable work and entertainment...sit at a computer...but no tactics to deal with that help. I was thinking about making an Ask HN thread recently but my last experience with that was pretty poor and the offer came from outside of that, but I saw this relevant post today and am desperate so here I am again.

Other than some older, specific stuff like a MBP 2011 17" antiglare screen that I had to sell(panelook.com says it had an RGB backlight but some dispute that), an iPad 2 on iOS (for at least 30min anyway), and a Windows Phone Lumia 635 on Windows Phone 8.1, Any LED backlit display I look at, and ALL modern ones I have found, on any brightness, filter or setting, or OS causes tingling in my face, back of head, and neck which turns into strain/pain/headache. I can replicate it. I can soothe it with time away or using the old, half functional CCFL laptop. I have tried 8 different panels in a Thinkpad, everything Best Buy has, borrowed from people, wasted money buying on eBay and testing. No success or answers.

There is a 10yo/168+ Apple support thread with no solution (was posted here not long ago in fact and most people blamed PWM or said it wasn't a big deal). A forum called ledstrain.org where people much smarter than me have tried to drill down through drivers and dithering and other options. Many of them reduce their quality of life further by using one of the 2 expensive and limited E-Ink displays out there, or hoard specific models of old displays and GPUs and outdated OS revisions they found work for them. I just cannot live even more limited like that since everything else about my life is already shrunk and reduced and miserable. Not being able to use or function around modern LED stuff is not tenable and there is no reasonable solution even on the horizon. Everything in my life is unstable and I have to solve this to get some foundation again. I am even entertaining the idea that this is all a big cosmic prank given how perfect the timing and specificity of this issue is. So, Loki, if you are out there I surrender. You win. Please give me a break.

rom16384 373 days ago [-]
I've researched these kind of symptoms, and the only common cause I could find on the internet from the few people that complained about this was that it was caused by an infection in the head/neck area. One person had an infected wisdom tooth, another one some problem with his neck.

Taking some Vitamin D may help (stay under the 4000 UI/day tolerable upper limit). There's a forum where people with similar issues used gather at http://bcomputermonitorpain.runboard.com/

As far as computer monitors go, you could either use an old CRT monitor, or try a e-ink monitor such as the Dasung Paperlike, or a modded Android e-ink tablet.

dm3730 373 days ago [-]
> reduce their quality of life further by using one of the 2 expensive and limited E-Ink displays out there

Could you elaborate on above? I did not understand the logic behind the sentence. E-Ink displays by themselves do not generate any light as they don't have any backlight or light emitter behind the display. That's why they work in bright sunlight. Some products with E-Ink displays have frontlights for night time reading. Is that what you are referring to? If so, given this article, just turning off the frontlight and using non-blue light sources for lighting is sufficient to avoid this, right?

hestipod 372 days ago [-]
I was stating that having to use the available E-ink displays is a reduction in quality of life because they are small (13"), expensive (~1000usd), and limited in function and performance which makes most web activities aggravating due to lag and ghosting. They aren't a solution, but just a more difficult workaround that shrinks life even more in my case.
walterbell 373 days ago [-]
Do you wear glasses? Have you tried an iPad Pro with 120Hz refresh + Night Shift? How much ambient light do you have when using the computer? Is the ambient light natural or artificial? If artificial, what spectrum/type?
hestipod 373 days ago [-]
Sorry I updated the post as I knew I would leave some things out as I am a mental wreck and this is long and complicated. I don't wear glasses. I have monovision from Lasik done 20 years ago and am starting to have presbyopia in the distance eye but it doesn't cause issues with CCFL displays or reading or anything else. I just have aapprox 3" window 10-12" from my face where neither eye is focusing well but displays are twice that far away and the doctor said it shouldn't matter or need correction. I have tried OTC readers with the close eye lens removed to try and close the gap and it doesn't seem to change this problem.

Refresh rates and software filters don't seem to matter so far. I have this strain by a well lit window with great natural light (sometimes oddly enough direct natural light can sort of "overpower" the sharpness of the display and make it look more like E-ink and it SEEMS less bad then but hard to tell once it begins. At night I have 4x 60w incandescents in my room with no real change overall. In stores with intense LED or tube lighting it happens just as fast.

walterbell 373 days ago [-]
Can you be more specific about "severe eyestrain"? E.g. if there is pain, where? Eyes dry, red? Difficulty focusing? Peripheral vision? Have you had an eye exam when the strain is present? When the strain is present, what happens if you switch to reading paper? Or switch to distance vision, e.g. looking out the window? How long does it take to recover from the strain when reading or looking into the distance?
hestipod 373 days ago [-]
The severe issue for the last 5-6 months since trying to use LED panels has been a tingling/tightness sensation around cheeks/nose that spreads to back of head/neck/trapezius turning into pain/ache. If you clench your eyes/face and lean forward you can feel the neck/upper back tighten too and it's all that area which makes me think something is triggering eye muscles to the degree they are making me tense everything else, but I have had lots of "intuition" about this that was never correct.

Eyes have always been dry since lasik, esp when living in forced air homes, but drops and blinking don't help this. No redness that stood out to me.No peripheral vision issues. No color distortions/double vision/ weird visual stuff but mild floaters I have had for 20-25 years. It can trigger anywhere from seconds to several minutes depending on the display. I have not had an exam when it's present. No insurance and scheduling/access is not quick.

Switching to any reading/distance but the LED displays soothes it with time and I feel no symptoms reading on paper. If its flared badly and other pain/stress/tension is high it can take some hours or a night's sleep to recover. On a good day with only a few min of strain induced, an hour outside is enough. Font size, antialiasing, resolution, different distros, drivers never mattered...even tried an all AMD laptop as some think intel drivers are the culprit but it was worse than most. The old display is supposedly the worst of all specs...low res/glossy/TN/CCFL/ has PWM and not great color gamut etc. Running Xubuntu on it, but that same distro and all others hurt on the LED laptops.

walterbell 372 days ago [-]
Have you tried an external LCD monitor that is big enough for you to increase the viewing distance to about 40"/100cm? As a simple experiment, move your current laptop further away, increase the font size and see if the time-to-eyestrain gets longer.

There are gaming monitors which have faster refresh rates.

Dry eyes need to be addressed, as the tear film contributes to clear vision. You can use a "sipper" bottle of water to keep your upper respiratory track moistened. Yawning can trigger lubrication of the eyes, if you are drinking enough water.

Do you have EMF sensitivity?

hestipod 372 days ago [-]
I have adjusted distance and font size and every other display parameter I can with no effect. refresh rates seem irrelevant. I use eye drops when needed but have had this dryness issue since lasik surgery in 2000. It's not so bad in non-forced air homes where it's not as dried out all the time but right now I am in one. I drink a lot of water. I don't have EMF sensitivity that I know of and again this only happens with LED displays so far.
walterbell 372 days ago [-]
Lenovo X1 Yoga has an OLED display, https://www.lenovo.com/us/en/laptops/thinkpad/thinkpad-x/Thi...

Dell U2711 monitor has a CCFL backlight, is available on eBay, http://www.tftcentral.co.uk/reviews/dell_u2711.htm

You've probably seen this LED vs CCFL monitor thread, it mentioned that CCFL screens are matte, is there any chance that your LED screens have a lot of reflections from objects/lighting behind you? https://superuser.com/questions/149362/is-an-led-monitor-bet...

This 2018 article summarizes display technologies for backlighting and phosphors for color accuracy, you can see a range of color spectra, https://pcmonitors.info/articles/the-evolution-of-led-backli...

This site has articles on eye sensitivity to light color, https://glarminy.com/2016/04/11/are-your-eyes-sensitive-to-l..., they sell a $20 kit with 8 filters that mimic the spectrogram of various commercial glasses for blue blocking or migraine relief, it's a cheap way to test how your eyes react to different filters+devices, https://glarminy.com/blue-filter-tester/

joveian 373 days ago [-]
I have no idea why the new displays would be different, but I did discover at one point that medication can affect eyes in surprising and wierdly lighting-device specific ways. In my case, I found that phenibut was causing a light therapy visor to hurt my eyes even on low, although strangely even fairly bright natural light did not. Even without phenibut I have trouble with the visor on high (a ReTimer that I got due to it being more greenish). Later I learned that taurine transpoters can also transport GABA and I suspect that this might have something to do with it (and that people who use high amounts of phenibut for long periods of time may be causing permanant eye damage via retinal taurine depletion). If you are taking medication and are able to try something else for a little while, there is at least a small chance that could help.

You may have tried this, but if it is muscle related then massaging your face and/or upper back might help. Not pushing, but grabbing and slowly twisting the muscles or skin. E.g. put three fingers at the bottom of your eye socket and bring your thumb up so it is an inch or a little less away from your second finger, then push your thumb up and fingers 3 and 4 down. You can repeat the same basic twisting motion over much of your face. Another one is grab skin/muscle between your thumb and two fingers and tilt towards the two fingers. Just lifting muscles (as tilting towards your thumb can sometimes do, or grab and lift) can also be quite helpful.

In the back of the neck and upper back it is easier to twist the muscle (but avoid the sides of the neck where there are fragile nerves) and additionally skin rolling can be helpful where you put two or three fingers opposite the flat side of your thumb, grab a small amount of skin (and potentially muscle too, although your focus should be on the skin) and then walk your thumb forward with your fingers, such that there is a raised area that moves in front of your thumb. If it feels "crunchy" at all or feels like it is sticking to the muscle (that you can't lift the skin as easily as elsewhere), go over it again until it doesn't, although not necessarily all at once since it can be exceptionally painful in some cases (in that case, just do a little each day and it should eventually not be painful). The twisting can usually be done in a way that affects just the skin or the muscle as well and both can be helpful.

Those three techniques (twisting or lifting muscles and twisting or rolling skin) are IMO the most useful ones anywhere on the body you can do them (also don't get too close to most joints), but just applying pressure to muscles doesn't really help in my experience. Lifting muscles on your own back is hard and not necessarily worth aiming for. For the face another good technique if you can is to put down your middle three fingers and keep them in one spot on your skin while moving your hand rapidly within a quarter inch or so of that spot.

The muscle/skin adherence particularly tends to happen on legs, most of all upper legs but often both, although the upper back/shoulder area is another area it frequently happens. If you see a massage therapist, look for Shiatsu, Tui-Na, or (not exclusively stretching focused) Thai massage since those styles are more focused on this kind of thing. But there may be quite a bit you can do yourself (depending on your other issues) that can be helpful. I guess it is unlikely to fix the real issue here but might at least help you recover faster.

hestipod 372 days ago [-]
"Later I learned that taurine transpoters can also transport GABA and I suspect that this might have something to do with it"

Can you clarify this? Phenibut affects GABA but above you said, taurine transporters can also transport GABA so I am not sure what you mean. Are you saying that Phenibut might hijack the taurine transporters so they cannot be used for Taurine? I have taken Zolpidem (which affects GABA) for sleep off and on for long periods but I am pretty sure I had this strain even when off it for 6 months or so so not super hopeful. Do I need to supplement Taurine then or is there some test for it in the retina you can have done? If it's permanent as you say that's not hopeful.

However once again, and I know you said it was weirdly spcific, but since this only happens on LED backlit displays I find it hard to believe it's something like that since that should affect other visual things.

joveian 372 days ago [-]
Sorry, I didn't mean to imply that I thought permanant damage was likely in your case (unless you happened to be taking a lot of Phenibut over a long period of time), just that it is possible that some medication could somehow be causing your problem.

At least GABA itself is transported by the taurine transporters and if you have enough GABA (as far as I know this has only been observed with vigabatrin use or rare genetic GABA metabolism disorders) then the retina will not get enough taurine and peripheral vision will suffer permanant damage that can only be detected with a special test until it gets quite bad. Taurine supplementation does prevent damage in that case.

Phenibut might possibly have the taurine transporter issue since (unlike Zolpidem) it is considered a GABA analog plus some people take quite a lot of it and even the lowest doses are quite a bit higher than the higest Zolpidem dose. Baclofen is similar to Phenibut but used in much lower quantities so it also seems unlikely to cause that trouble (and it actually doesn't cause my eyes to hurt). And I could be completely wrong about Phenibut having that particular issue, all I really know is that it makes my eyes hurt when I use the light therapy visor. Actually, I just remembered that taurine itself causes my eyes to hurt in the same way, so while it could still potentially be taurine transporter related it at least isn't a lack of taurine for my particular issue (sorry, I am also disabled due to sleep issues in my case and either that or some additional unknown issue affects my memory).

I see that Zolpidem does have multiple common eye related side effects, so somehow it can negatively affect the eyes. If you haven't been taking medication the whole time you have noticed the problem then that should be enough to conclude that it isn't medication related. Or if you are taking something else (like pain medication) but can't fairly easily change to something with a different mechanism of action then I don't think it is likely enough to be worth too much trouble (but keep the possibility in mind if you are ever in a position to test it).

For me it was even more specific, just the one particular LED light that caused the trouble, not my computer screen (which is older but I just checked and it is LED backlight) or brighter natural light, or anything else. I would have also thought it should affect other visual things but somehow it didn't (although in my case maybe it is somehow connected to the LED being so close to my eyes).

georgewsinger 373 days ago [-]
Implications for VR?
dang 373 days ago [-]
Submitted title was "Blue light is toxic to human eyes". That broke the site guidelines, which ask you to "please use the original title, unless it is misleading or linkbait; don't editorialize.


DmenshunlAnlsis 373 days ago [-]
Here’s the actual study, thanks to sci-hub: http://twin.sci-hub.tw/6979/4112e16f7195f7f33cd3e861c6345df0...
superkuh 373 days ago [-]
The post's URL actually includes links to the sci rep paper and the full text pdf paper is available from there for free for everyone. No sci-hub needed.



HIPisTheAnswer 373 days ago [-]
This is a huge problem. Neon light everywhere. I go out at night with sunglasses. The world is littered with light polluting salvages. That and combustion engines. I used to drive one. I used to behave criminally too. Light, sound, air pollution are real crimes. The world is littered with criminal brutes; anyone who uses bright neons, churns a combustion engine, or plays the stereo loudly. Soon the little people will be angry at the 'rich bastards who burn gas with their machines or waste power on overly bright aggressive lights'. Average person will then only afford a handful of KWh per month, and my life will be better. I wont stop any crowd from hanging gas/naphta burners or smashing neons tubes.
onecooldev24 373 days ago [-]
I use flu.x app on my mac. Is something like this going to help if you end up on your laptop for the most part of your day.
linuxyz 373 days ago [-]
For this exact reason, I've bought a e-ink 13.3" monitor from here https://www.indiegogo.com/projects/paperlike-3-a-smart-e-ink...

It's not cheap because it is the only one on the market. Apparently, constructors don't care about this future big health hazard...