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Re:Chemists discover how blue light speeds blindness by herf on Thursday August 09, 2018 @02:02PM (#17726716)
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:

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1751-1097....

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.

Re:Chemists discover how blue light speeds blindness by wpasc on Thursday August 09, 2018 @02:15PM (#17726865)
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?

Re:Chemists discover how blue light speeds blindness by Vesther on Thursday August 09, 2018 @05:17PM (#17728591)
Check out the FAQ for a PayPal donation link:

https://justgetflux.com/faq.html

Huge thanks to the author from me as well!

Re:Chemists discover how blue light speeds blindness by wpasc on Thursday August 09, 2018 @06:21PM (#17729068)
Thanks for telling me :) Paypalling now
Re:Chemists discover how blue light speeds blindness by guru4consulting on Thursday August 09, 2018 @10:51PM (#17730344)
thanks for the link. I have been using flux for years and recommending it to my friends too.. just donated a small amount..
Re:Chemists discover how blue light speeds blindness by robrichard on Thursday August 09, 2018 @09:50PM (#17730108)
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.

Re:Chemists discover how blue light speeds blindness by CardenB on Thursday August 09, 2018 @10:41PM (#17730305)
Can't wait to do this tonight! This will help so much
Re:Chemists discover how blue light speeds blindness by sundvor on Thursday August 09, 2018 @05:11PM (#17728544)
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.
Re:Chemists discover how blue light speeds blindness by tough_luck on Thursday August 09, 2018 @02:38PM (#17727118)
For my Samsung TV I use movie mode and also change colour temperature to warm.
Re:Chemists discover how blue light speeds blindness by rapnie on Thursday August 09, 2018 @03:12PM (#17727449)
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.
Re:Chemists discover how blue light speeds blindness by exhilaration on Thursday August 09, 2018 @05:13PM (#17728555)
On my Google Pixel, this is under Settings > Display > Night Light.
Re:Chemists discover how blue light speeds blindness by daveFNbuck on Thursday August 09, 2018 @10:10PM (#17730184)
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.
Re:Chemists discover how blue light speeds blindness by copperx on Thursday August 09, 2018 @06:49PM (#17729232)
I just want to remind everyone that LED backlights emit blue light that isn't eliminated by f.lux or similar utilities.
Re:Chemists discover how blue light speeds blindness by herf on Thursday August 09, 2018 @07:44PM (#17729529)
You might want to refer to our measurement project for some numbers:

https://fluxometer.com/rainbow/

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

Re:Chemists discover how blue light speeds blindness by hohenheim on Friday August 10, 2018 @03:29AM (#17731350)
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?
Re:Chemists discover how blue light speeds blindness by mediaman on Thursday August 09, 2018 @07:03PM (#17729305)
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.

Re:Chemists discover how blue light speeds blindness by abledon on Friday August 10, 2018 @12:04AM (#17730602)
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?

Re:Chemists discover how blue light speeds blindness by herf on Thursday August 09, 2018 @02:17PM (#17726896)
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.

Re:Chemists discover how blue light speeds blindness by phyzome on Friday August 10, 2018 @12:02PM (#17734527)
Do those numbers account for pupil dilation?
Re:Chemists discover how blue light speeds blindness by taneq on Thursday August 09, 2018 @02:12PM (#17726828)
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.
Re:Chemists discover how blue light speeds blindness by erikbye on Thursday August 09, 2018 @02:14PM (#17726849)
Windows 10 has this built-in, so does macOS.
Re:Chemists discover how blue light speeds blindness by arama471 on Thursday August 09, 2018 @02:17PM (#17726893)
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.

Re:Chemists discover how blue light speeds blindness by erikbye on Thursday August 09, 2018 @02:22PM (#17726945)
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.

Re:Chemists discover how blue light speeds blindness by wuliwong on Thursday August 09, 2018 @03:01PM (#17727356)
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.

Re:Chemists discover how blue light speeds blindness by erikbye on Thursday August 09, 2018 @03:28PM (#17727625)
Correct. I realized that opening line set the wrong tone and was unnecessary.
Re:Chemists discover how blue light speeds blindness by solarkraft on Thursday August 09, 2018 @02:44PM (#17727181)
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.
Re:Chemists discover how blue light speeds blindness by bvy on Thursday August 09, 2018 @06:48PM (#17729228)
f.lux screwed up how my MBP displayed graphics so I'm just using the built-in tool now. Unfortunate.
Re:Chemists discover how blue light speeds blindness by mi100hael on Thursday August 09, 2018 @07:16PM (#17729378)
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.
Re:Chemists discover how blue light speeds blindness by slothtrop on Thursday August 09, 2018 @08:43PM (#17729810)
There was nothing wrong with your tone.
Re:Chemists discover how blue light speeds blindness by saagarjha on Thursday August 09, 2018 @04:39PM (#17728267)
Night Shift on iOS and macOS also has a sunset-to-sunrise setting.
Re:Chemists discover how blue light speeds blindness by ycombinete on Friday August 10, 2018 @06:27AM (#17732073)
You'll almost certainly get down-voted on HN for whining about being down-voted, and for comparing it to Reddit.
Re:Chemists discover how blue light speeds blindness by mk89 on Friday August 10, 2018 @03:13AM (#17731285)
Just checked. Also Mac OSX has Sunset to Sunrise based on location.
Re:Chemists discover how blue light speeds blindness by visualstudio on Thursday August 09, 2018 @02:49PM (#17727238)
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.
Re:Chemists discover how blue light speeds blindness by herf on Thursday August 09, 2018 @02:56PM (#17727316)
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.

Re:Chemists discover how blue light speeds blindness by no_identd on Friday August 10, 2018 @03:12PM (#17736001)
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. :\
Re:Chemists discover how blue light speeds blindness by benrbray on Thursday August 09, 2018 @02:17PM (#17726884)
These are relatively new features, and they arguably wouldn't have been added if not for the popularity of flux ;)
Re:Chemists discover how blue light speeds blindness by erikbye on Thursday August 09, 2018 @02:28PM (#17727027)
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.
Re:Chemists discover how blue light speeds blindness by jakemauer on Thursday August 09, 2018 @03:50PM (#17727849)
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.
Re:Chemists discover how blue light speeds blindness by rootusrootus on Thursday August 09, 2018 @05:42PM (#17728787)
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.
Re:Chemists discover how blue light speeds blindness by epmaybe on Thursday August 09, 2018 @05:25PM (#17728648)
out of curiosity, how low are you going in terms of temperature?
Re:Chemists discover how blue light speeds blindness by bradknowles on Thursday August 09, 2018 @03:01PM (#17727354)
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.
Re:Chemists discover how blue light speeds blindness by opan on Friday August 10, 2018 @12:11PM (#17734600)
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.
Re:Chemists discover how blue light speeds blindness by oh_sigh on Thursday August 09, 2018 @07:28PM (#17729455)
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.
Re:Chemists discover how blue light speeds blindness by cmurf on Thursday August 09, 2018 @02:19PM (#17726909)
So does Fedora, courtesy of recent versions of GNOME with "Night Light" feature.
Re:Chemists discover how blue light speeds blindness by davidy123 on Thursday August 09, 2018 @03:59PM (#17727948)
Ubuntu got that too with the switch to Gnome. Before that, I used the open source https://github.com/jonls/redshift
Re:Chemists discover how blue light speeds blindness by chasote on Friday August 10, 2018 @07:29AM (#17732349)
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.
Re:Chemists discover how blue light speeds blindness by wpasc on Thursday August 09, 2018 @02:16PM (#17726872)
I wonder from whom they took the idea? f.lux has been around for YEARS (2009)
Re:Chemists discover how blue light speeds blindness by fouc on Friday August 10, 2018 @03:45AM (#17731413)
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.

Re:Chemists discover how blue light speeds blindness by opan on Friday August 10, 2018 @12:14PM (#17734624)
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
Re:Chemists discover how blue light speeds blindness by fouc on Saturday August 11, 2018 @10:07PM (#17742572)
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.
Re:Chemists discover how blue light speeds blindness by nnain on Monday August 13, 2018 @01:09AM (#17748115)
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.

Re:Chemists discover how blue light speeds blindness by fouc on Monday August 13, 2018 @10:18AM (#17750253)
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.

Re:Chemists discover how blue light speeds blindness by jensvdh on Thursday August 09, 2018 @06:39PM (#17729177)
I suffer from chronic photophobia thanks to Uveitis. Flux allowed me to keep my job.
Re:Chemists discover how blue light speeds blindness by Forge36 on Thursday August 09, 2018 @03:00PM (#17727348)
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)

Re:Chemists discover how blue light speeds blindness by hinkley on Thursday August 09, 2018 @03:14PM (#17727481)
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.

Re:Chemists discover how blue light speeds blindness by userbinator on Thursday August 09, 2018 @08:20PM (#17729715)
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.

Re:Chemists discover how blue light speeds blindness by Moru on Friday August 10, 2018 @03:37AM (#17731377)
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.
Re:Chemists discover how blue light speeds blindness by LeoPanthera on Thursday August 09, 2018 @04:26PM (#17728159)
Most/all modern monitors have presets, one of which is "store demo". All you've got to do is pick the calibrated preset.
Re:Chemists discover how blue light speeds blindness by no_identd on Friday August 10, 2018 @03:10PM (#17735992)
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:

https://argyllcms.com/doc/calvschar.html

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:

https://quickgamma.de/indexen.html

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.

Re:Chemists discover how blue light speeds blindness by jonhendry18 on Friday August 10, 2018 @11:45PM (#17738203)
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?"

Re:Chemists discover how blue light speeds blindness by no_identd on Sunday August 19, 2018 @03:26AM (#17793040)
>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.

Re:Chemists discover how blue light speeds blindness by henvic on Friday August 10, 2018 @01:45AM (#17730996)
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).
Re:Chemists discover how blue light speeds blindness by Moru on Friday August 10, 2018 @03:30AM (#17731354)
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.

Re:Chemists discover how blue light speeds blindness by rakotinci on Friday August 10, 2018 @03:29AM (#17731348)
You can just disable it for an hour. That's what I do at least.
Re:Chemists discover how blue light speeds blindness by ALee on Saturday August 11, 2018 @04:07PM (#17741280)
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.
Re:Chemists discover how blue light speeds blindness by akashaggarwal7 on Thursday August 09, 2018 @06:51PM (#17729238)
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!
Re:Chemists discover how blue light speeds blindness by spaceandshit on Thursday August 09, 2018 @09:32PM (#17730027)
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.
Re:Chemists discover how blue light speeds blindness by abledon on Thursday August 09, 2018 @05:07PM (#17728518)
how does eye color factor into this? I read that objects with certain colors reflect rays of the same wavelength.
Re:Chemists discover how blue light speeds blindness by sizzle on Thursday August 09, 2018 @06:06PM (#17728975)
Thank you for many years of f.lux. How would you say it stacks up against Nightshift in iOS and macOS natively?
Re:Chemists discover how blue light speeds blindness by zengid on Thursday August 09, 2018 @07:06PM (#17729317)
f.lux is amazing; thanks for your work!
Re:Chemists discover how blue light speeds blindness by ackfoo on Friday August 10, 2018 @08:21AM (#17732608)
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.

Re:Chemists discover how blue light speeds blindness by refurb on Friday August 10, 2018 @08:28AM (#17732653)
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.

Re:Chemists discover how blue light speeds blindness by ALee on Saturday August 11, 2018 @04:06PM (#17741278)
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.