Blue light from monitors no danger to eyes or sleep | Hacker News Reader

Blue light from monitors no danger to eyes or sleep

aerzteblatt.de

376 points_gfwu241 comments

I cannot comment on the long term effect of blue light, but at the very least i experience very significant discomfort when turning off any piece of software that makes the screen a more warm color (for example, f.lux on Windows https://justgetflux.com/ and something like Redshift https://help.ubuntu.com/community/Redshift on *nix), to the point where it makes me avert my gaze.

Due to me working primarily as a developer, i don't always need good color accuracy, so my current settings of screen color warmth are the following:

  Day: 4300K
  Sunset: 3000K
  Night: 2550K

In addition to that, i have a few smart lightbulbs that change to a more red color as the night approaches and gently dim more and more when i don't need to do any reading and just have to walk around the house. Subjectively, i'd say that it's better for me being able to fall asleep and experience a bit less eye strain (though admittedly, using a computer late into the night is never a good idea).

Perhaps the discomfort is just because of eyes having a hard time adjusting to noticeably different lighting conditions, but maybe there's more to it.

> Perhaps the discomfort is just because of eyes having a hard time adjusting to noticeably different lighting conditions, but maybe there's more to it.

Personally I suspect it this. I’m not 100% of how exactly f.lux etc works, but I’ve always assumed they work by applying a full screen filter that basically just reduces the Blue channel values, and possibly tweaks the other channels a tad to keep things looking reasonable.

Of course on of the side effects of doing that would be reducing the total amount of light your screen emits, and I assume this has to be true, because red and green would end up clipping if they were boosted to keep the light output the same.

As the app applies removes more blue, it further dims the image, and when you turn it off if restores all the channels, which also increases the screens total light output. And you basically get the same effect as opening the curtains in the morning (assuming your working in darkish room), with the resulting eye discomfort while they adjust to the increased brightness.

Best way to test this would be use the apps, and modulate the screen backlight to compensate for the reduced blue level, so the total lux emitted remains constant. Then switching back and forth would let you figure out is your eyes are responding to the blue, or just the total light level.

I guess your eyes will love VR goggles where the eyes are always (un)adjusted at optical infinity.

I agree, I find the orange tint just more comfy to look at at night, when I'm already in artificial light that has a lot warmer colour balance. In daylight the blue tint doesn't stand out, at night with warm white bulbs it really does look jarring.

I don't really care whether it's harmful or not, after all the amount of time I spend at the computer is harmful too.

Here's one more anecdote: I'm using the computer the whole time. I make the screens usually more bluish than redish as I don't like everything in orange tones. I prefer bluish-grays. I'm staring at the screen until late at night, more or less until just before going to sleep.

I've never experienced any bad side effects form that. When I'm tired I can always sleep instantly.

Funny enough I don't like bluish light besides on computer screens. All my lights are dimmed, and I prefer them being kind of orange. Actually my eyes hurt when being in places that use bright cold lights.

That makes the contrast (especially at night) between my computer screens and the ambient light quite significant. The screens seem the brightest lights in the room. Even they are also dimmed.

For the matter at hand I think there's one important observation to make: Most screens are just way too bright in default settings!¹ I usually dim screens to at least ~50%; when it's a bright one even down to ~30%. Not only that my eyes start to hurt after a short time looking at a screen in factory settings I get every time even severe headache after some hours looking at such a thing.

Most people I know don't dim screens. They like it as bright a possible as it makes the color experience best (and you don't need to dim the light in the room to be able to see something on the screen–especially during day and when there is sunshine around). The screen manufacturers also picked that up: Every new screen has an even more extreme maximal brightness than the previous models. It seems to be the "loudness war" of screen manufacturers.

A screen with warmer colors is less bright than a screen with cold colors (as the screens usually don't adjust brightness at the same time when fiddling with the colors). The back-light of a screen has a quite extreme cold color so making the screen more warm filters more of the back-light and makes the screen less bright as a result.

So if I would have to guess why some people experience positive effects from "redshift"-tools I would bet the effect is actually only related to screen brightness and has nothing to do with the color as such.

Whoever came up with this "redshift" theory was overthinking things, imho: It's true that the natural light gets more warm in the evening (as it is also in the morning… ;-)). But it gets also darker when night comes! That's actually the significant phenomenon in my opinion.

¹ Just try to look for some time into a 160W light-bulb… Try also a 40W model instead.

Thanks for this. I wear blue light glasses and keep my monitor screen on the Windows night light setting 24/7, and this is much better (I'm still going to keep the glasses, though).

Didn't read the OP, but this definitely helps. When you're on F.lux or similar and suddenly turn it off, it's like having a line of cocaine. Bzzzzzt! Focus mode!

I recall that a paper published by Oxford in a journal related to gerontology claimed that blue light accelerated aging of the retina. If I understand correctly, this article doesn't counter that claim outright, it just didn't find that risk with the low intensity of blue light coming from a typical monitor.

Tangentially related, that same Oxford paper (sorry I don't have a link and no longer have access to the paper) did however claim that light generated by red LEDs with sufficient intensity to leave a significant persistence effect after 3 minutes of exposure can reverse aging and damage in subjects over 40 years old although the sample size was just a few dozen people IIRC. It does so because somehow the retina's mitochondrial function is improved by light in the 650nm to 1000nm range.

Continuing on this tangent, I am 50 and have been exposing my eyes to red light for 3 minutes a day for many months and feel like my night vision has been restored. If I wake up in the middle of the night I used to see gray noise and now I can see darker black with better contrast. But I may be kidding myself.

https://academic.oup.com/biomedgerontology/article/75/9/e49/...

TLDR Brief 3 minute daily exposures to 670 nm (energies at the cornea were approximately 40 mW/cm2) for 2 weeks can significantly improve retinal function in those over approximately 40 years of age

Edit: 670 nm is deep red light

670 nm is red light, isn't it?

how does one expose their eyes to light in that spectrum safely?

I do not understand the assumptions behind this question. Can you clarify what you mean?

Is a red bulb enough or do you need a 670nm laser?

For the love of all that’s dear in this world, please don’t use a laser for that.

If you’re in a DIY mood, you can easily pick LEDs around that wavelength and they would generate more than enough light to even cause damage (if close enough).

I hope this was a joke. Don’t shine lasers in your eyes. https://en.wikipedia.org/wiki/Laser_safety

what assumptions? it was an honest question.

The safest way to do this is to step out in daylight when the sun is bright. Take a brief walk. You will also get a boost of Vitamin D that will cheer you up. Interestingly, in Yoga there is a pose called surya namaskar (salutation to the sun) that is supposed to be done early morning when the sun rises.

Can I assume you mean without sunglasses on? Living in FL I wear sunglasses religiously, but am out in the sun daily.

Yes, at least for sometime daily, but not in blinding sunlight that can hurt your eyes.

Where do you find this sort of light and how do you ergonomically do this?

I'd imagine your eyelids and the sun.

I picked up a great 670nm light from here: https://redlightman.com/

200+ for a red light? These are low power LEDs, not weaponized laser diodes. If you want a "deep" red LED then go to any hydroponic/grower supply store.

https://www.amazon.ca/HIGROW-Flowering-Fruiting-Spectrum-Enh...

Of course there’s a redlightman.com, but I am a bit surprised at the cost of these things. Is there something special about these “therapy lights” that a guy with a soldering iron and a handful of cheap 670nm LEDs wouldn’t be getting? I mean, the price of these finished products compared to my perception of the component costs is rather astounding.

This is the absurd reality anyone interested in led growing faces. And the saddest part is the uneducated fall for the many led scams out there. Many will advertise as 1000watts but then when you read the fine print they will say equivalent to 1000w. Or another good one they will name the model of the light “1000w LED Light” 1000w being the model of the light not the wattage. On top of it all many of these cheap lights are being sold for much more then they are truly worth to anyone. There are some reputable sellers who actually advertise the actual wattage used by lights but then you are really paying a premium. Like you said tho the reality is if you can solder these are easy to make. And if you live in the US you are really sitting pretty because all the parts are so cheap compared to me in Canada where I have to ship every part from the US. For about $600-$800US you can make a light that retails for closer to $2k.

Here is a very informative sight which goes over how to make several different led grow light builds ranging from 2x2 foot grow tent to an led for a 5x5. https://ledgardener.com/diy-led-strip-build-designs-samsung-...

In my bathroom I replaced the large bulb that is turned when switching on the vent with this bulb from Amazon: https://www.amazon.com/gp/product/B07TDP67LR/ref=ppx_yo_dt_b...

I use a small hand held concave vanity mirror and reflect the overhead light into my eyes. I wiggle the mirror handle to increase the spread. This is done while brushing my teeth since my electric toothbrush has a 3 minute timer.

Ergonomic ? yes. Practical ? for me yes. Safe ? maybe given the persistence effect matches what the paper said should occur. The Oxford paper used a small handheld red LED flashlight purchased for around $10 with a paper diffuser. I didn't enjoy doing it that way and stopped after a few attempts.

This bulb emits a lot of infrared light, probably its main purpose for the intended use. In Germany it is sold together with protective goggles for your eyes. So you should be carefull about the intensity of the light you put onto your unprotected eyes. With a reasonable distance it is pobably fine.

Please don’t look into IR light without proper protective glasses. Saves you from having to visit a ophthalmologist.

https://www.piliapp.com/screen/red/ looks legit

LCD display red should be pretty close to 670nm

but just as the OP states that a monitor's blue is too weak to do harm, its red is also too weak to achieve the W/m^2 needed for therapeutic benefit

Very interesting. Thank you.

Red light is also just fun to be in. It has a different atmospheric mood.

I have a gaming rig with two big front fans with red LEDs. I can swear my eyesight and mood improves just by staring a few minutes on them.

I wonder about presbyopia though. Would imagine that’s the holy grail of age-related vision decay? anyone knows of any promising research in this area?

I used reading glasses for years.

Then I started drinking a pint of kombucha, most days. I got my accommodation back, no more reading glasses! Other improvements too, e.g. blood pressure, skin elasticity.

I can't think of anything else to attribute the improvement to. I would never have guessed anything would help. (No guarantees, but would welcome other reports, positive or negative.) This is one of those "anecdotal" things where you might as well, because there is only potential upside, plus tasty hydration, no down. Like getting your Tdap booster (free at the drug store), because why not?

A pint of kombucha runs US$2.50-$4 at the supermarket. But I brew mine for <$0.20.

Ok, that sounds kind of whacky but very intriguing. Can I ask what age you are and if you measured your current accommodation power (like: how many diopters can you accommodate now)?

Old enough to notice skin elasticity. My reading glasses were +1.5. I still use them for extra-fine print, so there are limits.

Is your brew carbonated? The stuff at the grocery store says it's naturally carbonated but I have no idea how it all works

Kombucha includes also yeast which metabolizes sugars and releases CO2 so it has some natural carbonation like e.g. beer does.

I have a times added 1/2 tsp of dextrose ("corn sugar") before I tighten down the bottle lid, to boost fizz. (Beer brewing trick.)

As any skilled visual astronomy observer will tell you… you can train your eyes. Part of this is acknowledging that your night vision is best off-center and learning to foveate in a way which takes advantage of that, but a degree of it is also in just patient noticing. Skilled observers will pick up details in the sky people decades younger than them would miss, with the same view.

I've noticed I can see the Milky Way best when I observe off-center. As soon as I try to focus directly on it, it's not as clear. Bortle sky 4 probably, SQM about 21

That difference between center and peripheral vision isn't a defect. It has served us well for thousands of years. Center vision is for hunting, for tracking a target you want to chase/kill. Off-center vision is for noticing stuff in the bushes trying to kill you. So off-center vision is better at night and for detecting movement. That kept us away from the lions. Our acute center vision is tuned for daylight. It helped kill those lions when it was our turn to hide in the bushes.

Foveate. That's a new verb to me. From the context I take it to mean to direct the subject of one's visual attention to something else other than what one is consciously trying too. I guess it's like ethmoidating a perfume, or palatatating the mouthfeel of a fine wine, or phalangating rough textures.

Glad to see the language is still alive.

The best way to show this to non-observers is to show them the Pleiades. Most people can clearly identify a blobby cloud, but it disappears for them when they look right at it. You have to really look at it for a minute or two for the eye to pick up on it when focusing on it.

> But I may be kidding myself.

Luckily there's no requirement to justify a personal preference. I hate staring at LEDs/monitors without a warm filter even if it isn't hurting my eyes.

Same here. Can't go back, won't go back.

Have you considered alternatively switching to a warmer colorscheme like Gruvbox in your main apps? That way only the UI elements are warm while your video and other important windows remain unafflicted.

It's not just displays since LED is so pervasive for all types of lighting these days. The tail lights on modern cars are the absolute worst offenders to me when I'm driving at night. Wearing my yellow-tinted glasses is the only way to make it bearable.

Most screens are too blue. Not in a personal preference sense, in an objective sense. That's why monitor profiling and color correction are important. Similar to you, I find it grating to use most screens for a long period of time, but I think the better solution to that problem is just to profile your screens.

Our of curiosity, how would I do that? Or is this just something I should look up?

The easiest way is to pay a professional. Hardware required to properly calibrate a display is too expensive to make any sense to buy it unless you don’t care about money.

You won’t get great results by downloading profiles from the internet because every unit is different coming out of factory.

If you want to do it yourself, you'd get a colorimeter or spectrometer and then software that lets you use them to adjust your screen, like ArgyllCMS and DispcalGUI: https://displaycal.net/

There's a list of hardware supported by Displaycal here: https://displaycal.net/#instruments

For me it's ok to just set the color temperature to warm. But then I have to adjust all kinds of text highlighting color schemes which use pure blue for important text. These get too dim to read comfortably.

|I recall that a paper published by Oxford in a journal related to gerontology claimed that blue light accelerated aging of the |retina. If I understand correctly, this article doesn't counter that claim outright, it just didn't find that risk with the low | |intensity of blue light coming from a typical monitor.

I don't know the paper you're referring to but I'd be curious to read it. The most commonly espoused hypothesis that I hear is that increased exposure to blue light increases the rate of progression of age-related macular degeneration. Macular degeneration is essentially an accumulation of the byproducts of photoreceptor recycling in the retina. Certain people in the business of selling glasses latched onto this idea and it's spawned a cottage industry of snake oil salesman peddling dubiously effective blue-light filtering glasses and other gizmos. As far as I am aware there is no evidence that blue light actually increases the rate of progression of AMD in humans, and there's some compelling evidence that it has no effect.

https://www.aaojournal.org/article/S0161-6420(20)30727-2/ful...

The brightness of blue light matters. Its like measuring how radioactive a banana is and worrying about it.

I just remembered the dark sunglasses that some senior people wear that look almost like goggles, where the sides are also covered. I have never asked what are those for, but I imagine it's for preventing degeneration.

They're designed to fit over regular prescription glasses and block light coming in peripherally. We give them to everyone after eye surgery. They're not specifically designed to prevent macular degeneration. Try them sometime, they work incredibly well. I wear them now when driving.

What do you use for your source of light?

This is a 2018 HN thread discussing it:

https://news.ycombinator.com/item?id=17724995

I always thought that staring at monitors with blinding brightness is what causes retinal damage, not just blue light specifically.

That's one of the reasons I created Lunar (https://lunar.fyi): because having to lower the brightness of the monitor throughout the day, using its hard to find buttons, was such an annoying endeavor.

I’ve always used f.lux and now Night Shift simply because I like warm colors. I have all LED bulbs and strips in my house adapt automatically to <3000K after sunset just because it gives me a sense of warmth and coziness.

But now, thanks to your comment I stumbled onto the “intense red light” cult. I had no idea about this effect, I thought all intense light is bad for the eyes. But I hope someone tries to reproduce this study. Usually, bold claims like these can be the effect of cumulative small errors in the study process.

Have you heard of these new e-Ink PC monitors coming out of China? They seem like a promising niche use case for computing without the eye strain.

[1]: https://www.amazon.com/Dasung-Paperlike-Front-Light-Touch-Mo...

Wow. If anyone else found this intriguing and wasn’t aware of this this product category was emerging, their demo video is pretty impressive [0]. I’m balking at $1100 for 13.3”, but if they could get the price down a bit these would be great second screens for writing and email. I’d need minimal color support for coding, but that would also sell like hotcakes.

Edit: wow, they have a 25” monitor set to retail for $3k. Come on early adopters, get this price down for the rest of us!

[0] https://m.youtube.com/watch?v=vnUACe8Bsyg

My understanding is that the cost of sink is due to the patent holder keeping licensing costs high which keeps it niche. i.e e-ink is expensive so it is rare so it is expensive.

TBH at this point I have no idea why you need e-ink out side of low power situations. Quality VA panels have great contrast and viewing angles. OLED is even better.

At the prices e-ink displays are, a OLED screen would be more versatile and probably just as little eye strain (just use low brightness).

OLED screen don't seem to be happening for Computer monitors. Probably burn in issues. Dell introduced and quickly discontinued one model. Plus e-ink has no backlight whatsoever, yes OLED on a terminal screen can probably come close but i'm not so sure it is the same. e-ink is just in a class of its own. Was hoping Qualcomm Mirasol went somewhere or maybe Pixel Qi but alas nope. Still holding out hope for ClearInk. It might be the display that kills e-ink and becomes the magical display that everyone gets.

[1]:https://www.youtube.com/watch?v=51JaR7KTeKs

[2]:https://www.youtube.com/watch?v=ivauOg4FvpI

[3]: https://www.youtube.com/watch?v=zjJ2-cdhwMQ

At the moment there are several laptops with Oled panels and more are coming, so either the burn in problem is solved or not an issue in sufficiently long term. In fact car manufacturers started using OLEDs for the built in infotainment screens, and those famously sit and display the same image for hours at the time - sounds like it would be a poor choice for an OLED but clearly not.

Actually you are right. I'm sorry I totally forgot about that Samsung Galaxy Chromebook and there were a few more. My mind was thinking more of Desktop PC monitors as that is what the DASUNG is. Seems like a few options in the 27-32 inch are trickling out like the new LG monitor. Suspiciously it seem out of stock as soon as it launched, this is what happened to the Dell OLED. (EDIT: seems like other stores still have stock so disregard this) But yeah in the ~13 inch range there are a few laptops. There still seems to be some fundamental problem.

I have heard of talks that Apple is investing heavily into microLED and the next big tech and skipping OLED for Laptops/next gen Monitors. That might be where the rest of the PC industry heads as well.

I think it's just the same problem as HDR - there's absolutely no technical reason why we can't have a good HDR desktop monitor, but those really don't exist outside of a few extremely expensive models - yet good HDR tech is available on mid-tier TVs without any issue. I imagine it's just that the market for an HDR-enabled monitor is absolutely tiny, so the prices are very high and the choice is small. Same with OLEDs - there is demand for large(50-75") panels, so those are made en-masse and available at reasonable prices, but not so much for desktop-friendly 25-30" sizes. Laptops will budge that trend in 13-15" space but again, that does nothing for desktop monitors.

Maybe if you are REALLY good at convincing people, you can sell this to your health/eye insurance company as a necessary health related tool that should be covered under insurance. :D

> I always thought that staring at monitors with blinding brightness is what causes retinal damage, not just blue light specifically.

Just curious, did it ever occur to you how much more blinding even a cloudy day outside is? Adjust cd/m2 to roughly match the ambient brightness of the room, that's general ergonomic advise.

It always seemed to me that these "blue light harms your eyes" proponents had never spent a day outside.

FWIW some people don't adjust the brightness on their screens at all, that's where a lot of complaints about headaches and such come from.

I did some programming around light sensors calibrated to match human eye sensitivity, so I’m very much aware that outside sunlight (>50k lux) is much brighter than a monitor backlight (<1k lux measured at a distance of 30cm).

But I can stay outside in very bright sunlight for 12 hours (which I did 6 days a week before college while working in agriculture with my parents) and not have a headache or feel my eyes tired afterwards.

That’s contrary to what the monitor backlight does to me when staring at it even 6 hours at a time.

Not blinking often enough is probably the biggest cause, you are kinda forced to do that when reading/writing code and have to consciously make a decision to blink more often.

Focusing your mind very hard on the task is also probably a big cause of this and unrelated to light intensity or energy.

But having the monitor backlight adapted to the ambient light is what helps me the most to end up in a relaxed state after I finish working. I know it’s not something that will work for everyone, unlike most blue light filter ads going on nowadays about solving your sleep and vision problems.

I think using low brightness screens/bulbs/strips may have also increased my light sensitivity, because now I can’t stand a normal TV blasting its light into a dark room, or >1000lumen overhead light bulbs or staring at my phone in the dark without having the brightness all the way down (and sometimes using Reduce White Point).

>Continuing on this tangent, I am 50 and have been exposing my eyes to red light for 3 minutes a day for many months and feel like my night vision has been restored. If I wake up in the middle of the night I used to see gray noise and now I can see darker black with better contrast. But I may be kidding myself.

Maybe you can measure this with some placard on a wall with different shades of black strips (kinda like those old TV calibration screens) where you can see some of the black strips but not others and as time goes on measure if you can improve your visibility into it.

[1]:https://www.audioholics.com/home-theater-calibration/hdtv-ca...

Maybe some other chart like this might work better.

What kind of red light are you using for this?

Would just getting a red lamp for the office be enough for this?

On a note related to eye strain, but unrelated to blue light: the best solution I've found for eye strain is to wear reading glasses (or if you are near-sighted, glasses with an additional diopter or two) even if you don't need them. With the correct SPH value, the screen will be at optical infinity and your eyes will be fully relaxed.

Another pro-tip unrelated to the article: if you like to read at night in bed but find LCDs/OLEDs bothersome, I recommend trying red-on-black text. Particularly nice for glasses wearers who are bothered by chromatic aberration.

---

On the subject of this article: does anyone have a translation of the study itself? While I'm not at all surprised that there is no retinal damage, I'm very surprised that they found sleep was unaffected. Blue light does more strongly activate ipGRCs, after all.[0] And that clearly suppresses melatonin.

I'd also like to know if by blue-light blocking lenses the article means the ones that block "high-frequency blue" light (Zenni brands these as "Blokz Blue Blockers") which are probably useless because the violet/UV light they block aren't actually produced by most displays, or if they mean the orange-tinted glasses that obviously cut into blue light.

[0]: https://en.wikipedia.org/wiki/Intrinsically_photosensitive_r...

My eyes take time to adjust to the increased magnification, triggering a brief headache. Then, after I take them off after a long screen session, they adjust back to my normal sight, triggering another headache.

However, staring at the screen intensely without them also triggers a headache.

My solution: make everything bigger on the screen. Terminal, browser, text size. Makes me feel like a grandpa, but it works. I've even reduced my resolution to scale everything.

My eye sight is 20/20 and I have no problem reading small text in books, but something about the screen just makes me feel so much more relaxed and comfortable when everything is bigger.

I did this not for eye strain but so I would stop craning my neck forward, and it works fantastic.

I just put 2x scaling on all the screens (all 4k+, so do what works for your screens),

I’d say from there I slightly scale down most websites using the browser to 90% or 80%.

Yes I do this too, for exactly the same reasons. Also makes me feel like a grandpa, but who cares. Also it makes me realize how frequently apps fail to account for large system-level font sizes.

Do you wear glasses often, given that you have 20/20 vision?

No, my eye doctor actually just prescribed me a set only for looking at screens because it increased the sharpness (apparently one of my eyes has stronger visual acuity than the other, and this imbalance is exacerbated when staring at screens but also I was told this is pretty common). I spent a lot of time trying to "hack" a solution for my eye strain and constant headaches, so I tried a bunch of things, including readers.

I also recommend an onscreen magnifier that appears and disappears on hotkeys. I use MacOS' built-in one, set up to show when ctrl-alt are held. I have only moderate myopia, but the magnifier makes it much more comfortable to look at small-ish things on the screen. There's an image that you wish was bigger? No need to open it separately or bend forward—just mash the keys, bam, it's half the screen now.

On the non-hidpi screen the magnifier pretty much took me to the days of 800x600 screens, causing frequent reflections on how the times change. But on hidpi, it's more like I get a 1280x800 screen in the magnifier. Works like magic for images with small details, e.g. aerial photos: almost like peeking through a telescope.

Have you compared similar font sizes on different monitors? I’ve realized monitor quality makes a big difference when reading text for hours on end. Some produce very sharp text, others not so much.

All retina monitors have had impeccable text sharpness since 2012. However, for desktop monitor sizes anything less than 5k isn't acceptable.

It's possible that the brief headache is due to confusion between vergence and focus. I.e., your brain is going "my eyes are converging a point 30cm away, so why am I focusing as though it's infinitely far off?!"

If this is the case, adding base-out prism to the lenses could (in theory) solve problem.

https://www.eophtha.com/posts/fun-with-prisms-in-ophthalmolo...

The study (linked at the end of the article) is published in the American Journal of Ophthalmology; no English translation needed.

https://pubmed.ncbi.nlm.nih.gov/33587901/

Oh! My mistake. I thought the article was about some newly-published German study and that the English links were just references to other, related studies. This is the other study they linked ("Does iPhone night shift mitigate negative effects of smartphone use on sleep outcomes in emerging adults?"): https://doi.org/10.1016/j.sleh.2021.03.005

It's possible I'm missing something, as neither seems to be about retinal toxicity (i.e., "danger"), just eye strain and sleep duration/quality. The article you linked is about eye strain w/ "blue blocking" lenses, and the other is about the "night shift" feature of iOS.

(For reference, the blue-blocking lenses in the article you linked were ones that

>filtered blue light by front surface coating between 10% and 30% in the range of 400-500 nm. These lenses almost completely blocked transmission below 400 nm and had approximately 95% transmission between 500 and 700 nm.

so they are of the "Blokz" type that probably don't do much for computer/phone use. While displays do produce light in the 400nm-500nm range, the lenses described only attenuate it by 10%-30%.)

To state the obvious, just in case, the old “if it hurts you to do X, do it less” applies to eye strain as well.

If sitting 8h in front of a computer hurts your eyes, taking regular and irregular pauses, changing focus, printing long documents etc. will of course dramatically help and probably be the best effective way to reduce it.

I find that wearing reading glasses helps me stay focused in an office environment. My computer is in focus, but anything farther away is a bit blurry and therefore less distracting.

Myopia progression isn’t related to eye strain or muscle use. Over focusing on the peripheral parts of the retina tells the eye to grow longer because it thinks it’s over focusing, especially in youth. You should wear corrective lenses as little as possible especially if you do work that keeps your peripheral vision in focus like reading or using a screen.

In that last sense are you referring to young people?

What do you mean by "over focusing on the peripheral parts of the retina"? And if this is true, could one reverse myopia progression by doing the opposite?

The eye grows automatically in response to what is in focus. If too much is constantly in focus the eye grows longer to blur it. This is especially important in peripheral vision which is why lenses are finally coming out with blurred edges to slow myopia progression. Ophthalmologists who don’t know this and don’t tell people to use lenses as little as possible and dont think screens cause myopia are negligent (and hopefully will start getting sued until they learn) especially when prescribing lenses to children when this matters most. The eye generally stops being able to respond to the over focus stimulations in adulthood. And children with unnecessarily worsened myopia from negligent doctors are at higher risk for permanent blinding illnesses earlier in life and more frequently. If your eye doctor doesn’t know about low dose Atropine for children, then leave them (or explore legal options if your child’s myopia has gotten significantly worse). There is no known way to reverse the elongation of the eye and therefore reverse myopia, for now it’s permanent. Any claims to reverse myopia without surgery are pure quackery, like the Bates method.

>On a note related to eye strain, but unrelated to blue light: the best solution I've found for eye strain is to wear reading glasses (or if you are near-sighted, glasses with an additional diopter or two) even if you don't need them. With the correct SPH value, the screen will be at optical infinity and your eyes will be fully relaxed.

This is interesting. I'm reminded of the oft repeated recommendation to "look away from your screen at something far away" every 15 mins. I wonder if you could just switch glasses to a prescription that make your eyes believe they are focusing on something at a distance. How would you figure out the right prescription for this use case?

Headline is incorrect regarding danger to sleep.

The study cited[1] regarding sleep only compares regular iPhone usage and iPhone usage with night mode, and found no benefit from the night mode.

This is a weak result, since even with night light modes screens still emit a fair amount of blue and green light.

[1]: https://www.sciencedirect.com/science/article/abs/pii/S23527...

I use f.lux on my Mac [1] and Night Shift on my iPhone since on the latter there is no alternative thanks to Apple's limitations.

There is an immense difference between the two. Night Shift just tints the screen lightly. The colors are all still there, including blues.

f.lux kicks in gradually, but at its peak my screen is completely orange and colors are not discernible anymore.

Empirically, I can see why Night Shift makes no difference.

Edit: On the f.lux website they cite extensive research on the effects of blue light on sleep. [2]

[1] https://justgetflux.com/news/pages/macquickstart/

[2] https://justgetflux.com/research.html

The backlight is blue in hue. It’s imperceptible to us because we look for colour differences. But if you compare the “white” of your iPhone screen to the “white” of a t-shirt in the sun you will notice that it’s still blue light.

Computer screens have no option to not emit blue light, all their light is a tinted blue hue.

This sounds stupid because _obviously_ screens emit colour! And they could just cut out the blue colour!? But the backlight is always emiting some amount of blue light.

https://bluelightatnight.com/the-problem-with-flux/

Wrong, there are many OLED monitors and TVs which do not always emit some amount of blue light. All blue light pixels can be turned off.

OLED helps a lot actually!

That is talked about in the article I posted.

I didn’t want to copy it all out verbatim.

I'm still hoping for OLED monitors or something similar.

Until now the best I've found if VA panels. Not the best in viewing angles and color accuracy, but they have pretty good contrast. And to me contrast is what matters most. With higher contrast (black being black) it's much easier to work with less backlight, and that in turn makes for less eye strain.

"Wrong, there are many OLED's"

Many? They are less than 1% of current fleet of computers, I don't know a single person that has one. Still very expensive.

FYI, since the last few years, most recent iPhones are OLED.

iPhones with OLEDs and TrueTone can (and do) compensate for this.

The OLED removes the backlight, so no requirement to emit blue hues ever, and TrueTone matches the screens colour temperature to surrounding light sources, so colours look like should if the screen was a reflective surface, rather than an emissive surface.

You are confusing colour temperature with emitting blue light.

Natural sunlight at noon in a blue sky is >8000k. your screen will be 5600k or there abouts. The reason why they look blue is because you are normally inside, with low colour temperature domestic lights. taking your device outside at noon on a clear sky day will not make your screen look blue. It'll make it look very dark.

> Computer screens have no option to not emit blue light, all their light is a tinted blue hue.

I mean thats not really true. Yes an "off" LCD will leak light, but it wont be anywhere near as much blue light as "low" colour temperature white screen. There are standards for this sort of thing to guarantee colour correctness. HDRI LCDs should be almost completely dark when black.

but your main point; no they shouldn't be tinted blue. They should assuming they are not utterly rubbish be emitting a decent range of of spectra. The filter efficacy of the R,G and B pixels is pretty good. Its not perfect, but its way below anything that we can meaningfully detect with our eyes. Especially as eyes are not absolute sensors.

In the research page linked, there is extensive research on the effects of bright light exposure to circadian rythms, which may indeed alter quality of sleep by altering natural biorythms (note that no effect is produced on sleep itself, but rather on its timing, and this in turn affects its quality).

There is, however, very little research linked to blue light in particular, and it is inconclusive and contradictory. The best source they cite is actually against the hypothesis:

"Occasional claims that the light sources with emissions containing blue light may cause eye damage raise concerns in the media. The aim of the study was to determine if it was appropriate to issue advice on the public health concerns. A number of sources were assessed and the exposure conditions were compared with international exposure limits, and the exposure likely to be received from staring at a blue sky. None of the sources assessed approached the exposure limits, even for extended viewing times."

On a more subjective note, how they bury the actual research below tons of related-but-not-really articles, pop media links, and "explanations" makes me suspicious.

And mind, I do set my screen to redder tones in the evening and find it pleasant and probably helps me set the mood to go to bed, but I don't think research supports physiological or health reasons to avoid blue light or spend money on blue light avoiding, as the OP link seems to say (I don't read German :(

For your iPhone, you can use Color Filters under Accessibility -> Display & Text Size -> Color Filters. Set it to Color Tint and play around with the sliders to your liking (I personally set intensity to ~85%, hue ~8%, and compound it with Night Shift). I also use Reduce White Point (also located in the same place) to further reduce the screen brightness. With these two features, you can get your phone very similar to f.lux.

You can set these two features as active in Accessibility Shortcuts (bottom of the Accessibility menu), allowing them to be quickly toggled by triple clicking the power button. As an alternative gesture, you can also set Accessibility Shortcuts to activate via triple tap on the backside of the phone (Accessibility -> Touch -> Back Tap).

People with circadian rhythm disorders use very bright blue lamps in the morning to reset their circadian rhythms, simulating the blue skies our ancestors once experienced.

Our ancestors? I feel sorry for you.

where do you live where the sky isn't blue?

The sky is not blue, it's violet.

The blue sky spectrum presents across 450–485 nm, the wavelengths of the color blue. Violet is 380nm. Although, perhaps I’m being too literal and your comment went over my head.

https://en.m.wikipedia.org/wiki/Diffuse_sky_radiation

Violet is even shorter wavelength than blue, so it's scatered more than blue, but we see blue because our eyes "trick" us ;)

https://www.forbes.com/sites/briankoberlein/2017/01/11/earth...

only if you are an ancient greek.

the wine-dark sky reflects the color of the sea

England, sky is a billion shades of grey. We only get blue on Christmas day, and The Queens birthday.

Me, smiling in Caribbean

Worth noting that the article itself doesn't seem to cover the blue light / sleep question except to link to this 2021 paper, which is fortunately in English!

https://doi.org/10.1016/j.sleh.2021.03.005

Duraccio, K. M., Zaugg, K. K., Blackburn, R. C., & Jensen, C. D. (2021). Does iPhone night shift mitigate negative effects of smartphone use on sleep outcomes in emerging adults? Sleep Health, 7(4), 478–484.

Quotes from the paper:

> There were no significant differences in sleep outcomes across the three experimental groups. Post-hoc exploratory stratified analyses revealed a significant main effect of phone condition on sleep efficiency (P = .014) and WASO (P = .013) for participants averaging more than 6.8 hours of sleep per night, with the no phone condition demonstrating the best sleep outcomes.

In other words, if you want to sleep better, don't use your phone at night. My assumption is that any improvement in sleep due to a filter would be the result of dimming the screen, since changing the native color temperature of the screen limits its maximum light output and creates a dimming effect unless the brightness is increased to compensate.

> However, there is little evidence to support the use of short-wavelength light blocking devices, such as filtering glasses or the Night Shift function, to improve sleep quality in healthy populations, although there may be a small benefit for people with insomnia.

That is interesting. Not sure how crucial this studys circumstances are for looking at this, but personally I could swear that my phone screen without a blue light filter keeps me more awake. Maybe that's just a fallacy because it definitely feels way more pleasant for me.

I too find blue light more pleasant than red, and night shift filters make me irrationally angry because of the loss of color accuracy.

I recognise the same thing, but not limited to phone screens. I associate the warm dim light of incandescent bulbs with evening and winding down. I also associate bright blue light with activity and being awake.

It’s anecdotal, of course. But whenever I’m winding down and I see a bright light I can just feel my body wake up a little.

I wonder if that’s actually as physical as it feels or if it’s caused by the associations.

> such as filtering glasses or the Night Shift function

Those two are very different. Some filtering glasses can remove the entirely of the blue spectrum, while the night shift function only reduces (but not eliminates) it.

Maybe so, but you'd still expect anything capable of removing a good bit of the blue light to still show a significant improvement in sleep quality, even if the effect was not as large as with "complete" blue light removal.

I suspect that the darkening effect of changing a screen's color temperature along with the placebo effect can explain a good bit of this. Most people are not very good at assessing something as vague as "sleep quality". Robust studies are very much needed.

Full text in English (I posted a link to the translated version by Google, which was automatically edited to the original):

Munich - LED displays and so-called blue light are not a danger to eyes or sleep. This is explained by the German Ophthalmological Society (DOG).

Blue light belongs to the visible part of the electromagnetic spectrum and is characterized by energy richness. "Nevertheless, the light intensity when using electronic devices is far too low to cause retinal damage to the eyes," explained DOG expert Michael Bach of the University Medical Center Freiburg.

The natural illuminance in the free one with cloudy winter sky amounts to in our latitudes approximately 5,000 lux, on a sunny day up to 100,000 lux. A computer screen, very brightly adjusted, remains at a distance of 50 centimeters, however, below 500 lux. "Even if children sit for hours in front of screens due to corona-induced distance learning, at least blue light eye damage is not to be feared as a result," the vision researcher noted.

Contact lenses that block blue light also did not protect against eye fatigue during screen work better than standard contact lenses, according to a recent study (American Journal of Ophthalmology 2021; DOI: 10.1016/j.ajo.2021.02.010), the DOG said.

Studies: No evidence of health risk from cell phone radiation Smartphones taboo for young children Death and illness cases: Samsung apologizes DOG expert gives the all-clear also in relation to possible sleep disturbances, which could cause the blue light by evening reading at electronic devices. This assumption, too, has since been refuted by a study, he says (Sleep Health 2021; DOI: 10.1016/j.sleh.2021.03.005). Bach therefore recommends simply avoiding maximum display brightness when reading on an electronic device before falling asleep.

DOG President Hagen Thieme thinks it is important to bring these research findings to the general public. "They serve to educate and protect consumers from misleading advertising and unsettling false reports that pursue purely commercial interests," said the director of the University Eye Hospital in Magdeburg.

Translated with www.DeepL.com/Translator

Article is from a reputable, highly prestigious magazine for doctors in Germany. Full study here: https://pubmed.ncbi.nlm.nih.gov/33587901/

Off-topic: deepl, in my experience, is a much accurate/nuanced translator than Google/Microsoft.

In my experience with Japanese, DeepL is good at making plausible but inaccurate sentences.

A good visual illustration:

https://www.theverge.com/21298762/face-depixelizer-ai-machin...

The study merely finds no significance difference. Which does not equate to no effect. More participants could have led to a significant difference.

If the authors wanted to claim that there was no significant difference they can perform another statistical test for that where you invert the null and alternate hypothesis. It usually requires a bigger sample size because it is a harder hypothesis to prove.

If you are going to downvote me please explain to me why I am wrong. I am training to be a biostatistician so it is of professional interest to know if I have failed to explain something correctly or coherently.

I don't know why you are being downvoted, this is 100% correct. It's the whole reason we do things like power analysis.

Thanks, I am glad to know my half finished Masters degree isn’t a total waste :)

Generally, you'd have to find an English language source or wait till one appears. Lots of moderator halakha on this:

https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...

If that were true f.lux wouldn't be so significant in my experience. I can't watch TV or use my nintendo switch for very long without suffering from pretty bad eye strain that could evolve into a migraine headache and a night of rough sleep. On my laptop it was the same way too, until I installed f.lux. Same is true for every other device I've been able to install f.lux on.

Agreed. It’s possible the improvement is due solely to a reduction in total light output (which I assume is a side effect of reducing blues) but something about it really seems to help. I still wish my monitor could go dimmer.

It is an anecdote but I also much prefer redshifting all my displays. At this point, it is really uncomfortable to look at a blue screen on someone's phone. If the science isn't finding an effect, they are either not measuring the right thing or they are not measuring it with a large enough sample size.

I agree. https://github.com/jonls/redshift has been a gamechanger to me. Hint for those with desktops: redshift may fail to detect your location so you can use -l lat:long to set it.

Is that only because it’s bright and contrasts strongly with the darkness? A dim one without a color filter looks fine to me.

Well I always turn my monitors to the lowest brightness at night but when the program turns down the blue tones I assume it reduces the light output further. That may be the main effect that helps (brightness reduction) or it could be that reducing blue specifically helps. I’m not sure.

> If the science isn't finding an effect, they are either not measuring the right thing or they are not measuring it with a large enough sample size.

This is a very dangerous idea to have. Placebo is a very well known effect.

True, but poorly designed studies and non-replicated results are also very common. I think if a majority of people find some effect to be anecdotally true I’m their own lives (“using flux makes my eyes hurt less and I fall asleep more easily”) then you should need to meet a high standard of very rigorous science to prove them wrong.

Placebo is controlled for in these kinds of experiments by using a comparison group exposed to a carefully designed placebo.

To be very clear, you can test for the abscence of an effect. It is a little bit more challenging than finding a "true" effect, but it is feasible.

It is a dangerous, and common, misunderstanding to not distinguish between "no significant effect" and "statistically significant zero effect".

It sounds more like a background contrast issue, if you dimmed your device would you still have it even without warm filters?

If you are serious about the effects, don’t bother with the software just get yellow glasses so you don’t need software. I don’t have any issue with blue light as long as the screen is not a high contrast to the background.

Wear a pair of glasses or this convenient software on every device I use that adjusts it based on my location...

Personally I prefer good hardware, no installs, no updates, software has a lot of random issues and something like the iPhone doesn't have it, wearing glasses is one and done.

iPhone doesn't have it? What iOS version? 5?

I never realized just how blue many computer screens were until I got my first calibrator along with a new panel. In general these days I target all my screens to around 6500 kelvin/D65, screens could be easily be 9300 kelvin out of the box.

You get used to these color casts, but bright screens with blue casts do seem to cause more eye strain... unless you just turn the screens brightness down? like, to around the sRGB spec screen luminance level?

I have tried f.lux and the equivalent shift programs that are now native to iOS etc. My experience has been that they have no impact, at all, when compared to simply turning down screen brightness. My uneducated guess is that most of the impact of f.lux or equivalent is due to the fact that it unintentionally "dims" the monitor, rather than actual color temperatures of light mattering.

The primary benefit of f.lux is that blue light (morning blue sky) triggers wakefulness, but red light (sunset) triggers sleepiness.

I can go to sleep an hour and a half earlier if I use f.lux or a similar "turn the blue channel off" app.

> If that were true f.lux wouldn't be so significant in my experience.

Let me introduce you to something called the placebo effect..

Could be it's because f.lux dims white ? I find screens with white very white (for a lack of better word) like Apple's, oled screen etc. hard to use, I can't focus when the background is white and generally try to reduce the output or dim screen. My desktop screen's brightness level is at 0, except when there's a lot of sun then I crank it to 30% max. I have an old dying saartphone and new ones are not as comfortable and I blame the screen.

I wish they made another e-ink phone.

I have never had problems with sleep because of blue light from my monitors, nor can I say wether or not it's "dangerous," but in my experience it definitely does cause temporary eye strain. In a dark room, using a blue light filter makes a world's difference when it comes to how "dry" my eyes feel, how much I need to squint, and the eventually developing head ache. Granted my methods for testing this aren't very scientific, but it does help me, even if it doesn't make a difference in the long run.

I bought some blue light filtering glasses five or so years ago (GUNNARS, back when I was more into gaming and they were popular) and if I don't use them for a day, or even part of a day, my eyes are noticeably more fatigued and drier that evening. I highly recommend getting a pair.

For those who can't find brand name blue light blocking glasses in their region, yellow or orange tinted plastic safety glasses are available everywhere and they work just as well.

That has been my experience too. Using an app like Flux https://justgetflux.com/ to change the "warmth" of the colours on the display definitely has a soothing effect on the eyes, and reduces strain on it. But I too don't believe it disrupts my sleep in any manner. What does disrupt my sleep is when I am doing something interesting in the computer or phone, and my brain tries to fight off the sleep - I think addiction to social media, games etc. are a better explanation to why people are losing sleep to computers and phones than the "blue light effect".

It must be doing something because when I got my blue filtering lenses I could put them on and feel physical relief of pain/strain in my eyes

Same experience here, has made a world of difference

Depending on how a statistical experiment was designed, I could imagine a variety of results though

I guess most of this is because it makes your screen darker, not because it's specifically filtering blue. Most displays are set up way too bright.

Same here but maybe it's simply a case the filtering out blue reduces the total light intensity enough to be easier on the eyes. Wonder if similar results could be accomplished by filtering red instead or simply turning down the brightness on our devices and using lower lumen bulbs around the house.

Blue light carries the most energy, so I imagine filtering it out has the greatest effect compared to those other mitigations.

What do you mean by the most energy ?

Blue light has more energy per photon (energy is proportional to frequency). Therefore, it is better at ejecting photons from atoms and damaging molecules than other visible light. UV is even worse.

Also, semi-related, eyes are less sensitive to blue light, so if you want to achieve the same effective perceptual brightness, you need more photons if it's a higher color temperature.

Kind of nitpicking, red light energy is around 2eV, while for blue light around 2.5eV, it's not like it's a very sensitive difference.

UV is much higher energy, in the range of 40 eV~.

From another comment summarizing contents it seems this research focuses on danger of permanent damage. Just because there isn't permanent damage from blue screen light doesn't mean that it can't also be more comfortable to you and promote healthy sleep to filter it out

I wonder if it's a way to decrease brightness while maintaining better visibility.

Not really what you were asking but I thought I'd throw it out there anyway.

On an iPhone, Settings > Accessibility > Display & Text Size > Color Filter > Select Color Tint > Select Deep Red > Intensity 100% & Hue 100%.

Go back to Accessibility and select Accessibility Shortcut > Select Color Filters.

When I'm reading in bed, I triple press the right button and it turns my red filter on. I've noticed a significant decrease in eye strain and I find it doesn't keep me up at night.

I know that is counter to this post, but it works for me so might be worth a try.

Great tip.

I’ve just done this and it’s perfect for nighttime HN reading!

Doesn't mean it's dangerous like the ads say

The human eye has quite a lot of chromatic aberration, and if you basically get rid of the blue it makes it a lot easier to focus on distant things.

My vision is perfectly corrected for infinity when I have my glasses on under normal conditions, but at night when my pupils are wide open, I simply cannot focus to infinity at blue wavelengths.

I also sleep better on days when I wear my glasses (which have a blue blocking coating) as compared to my contacts. Unfortunately the contacts provide better vision, thanks to my astigmatism.

How does astigmatism help to get clearer vision?

It doesn't. But my contacts correct for my astigmatism much better than my glasses do (which may or may not have any astigmatism correction, I'm not sure). So the vision I get out of my contacts is sharper than my glasses, but my glasses offer blue blocking. Tradeoffs.

I used to get frequent headaches and eye strain during work. I bought blue light filtering glasses, and the problem went away instantly and hasn't come back. Placebo or not?

None come to mind off hand but there’ve been countless studies on ambient blue and red light and how it effects sleeping. Haven’t Boeing and AirBus also studied this extensively wrt jet lag?

I don't know but someone needs to tell Amtrak, because their busses are illuminated with blue light on overnight rides and it drives me insane.

I think the bigger picture is _sleep hygiene_. Don't use your LCD device before bed. Don't have all your birght LEDs blaring in your house until midnight.

We evolved as diurnal monkeys, with bright days and moonlit nights, staring at a mix of near and distant focal points all day. Now we stare at a glowing blue rectangle 1-2' from our faces for the majority of waking hours.

Break the cycle. I for one read (paper books, or on tape) after 9pm. I have zero devices, clocks, LED's, etc in my bedroom. My Phillip's Hue lights step down and dim as the evening progresses, rather than lighting my house like a bus station. I sleep much better than I used to when I sat in front of 3x blaring LED monitors until 1pm each night.

Good luck.

Did you mean 1am?

Do we know if it's really about the light? For me, I suspect that computers and phones are just hyperstimulating. It prevents winding down and preparing to sleep, so it's about the medium, not the technology.

Same rule, different explanation, same result.

I have found that using a dedicated e-reader with a front-lit e-ink display does not cause me any trouble with falling asleep.

This headline makes a huge leap from a single study that found a lack of evidence of permanent damage caused by blue light in screens to a claim that it is no danger at all to sleep. "We didn't find evidence of danger" !== "there is no danger". And anecdotally, many of us know from experience that blue light affects our sleep. So, I'm skeptical of this headline.

A lot comments claim that blue light does not affect their sleep, and the others claim it does. Well, blue light does not affect "everyone" the same way "all the time". Computer screens did not affect me until around 15 years ago when I started having trouble sleeping- basically lied awake in bed for 1-2 hours after heavy screen usage before falling asleep. I started using f.lux and the problem instantly went away. Now I use built-in night light setting in the OS, and if that is not an option, manually reduce blue level of the monitor RGB settings.

I have no opinion on the effect of blue light on wakefulness. But I really really like the warmer, “quieter” screen mode in the evenings. It’s like having a dim incandescent lamp on in the corner. It’s cozy.

Some of my co-workers use reduced blue light on their monitors, and when I need to work with them on something on their machines, I experience significant eye strain because of absence of the blue light. I just can't see as clearly as normal without the blue light. I'm not sure how they adapted to it, or perhaps they experience the same eye strain but they think it's OK because they are convinced that blue light hurts their eyes. Eye strain hurts your eyes that's for sure.

Curiously, your eyes cannot actually focus blue light, and your vision acuity does not depend on focusing blue light.

This was noted when defining broadcast TV standards, and the blue component of the signal has always been radically reduced -- not in intensity, just detail, because it makes absolutely no difference. The bandwidth stolen from green was given to white and green, where it is useful.

Is Deutsche Ophthalmologische Gesellschaft (DOG) really authoritative on the topic of sleep? Eyes are not the dominant organ relevant to sleep. Surely it’s the brain.

I’d like to hear an opinion from the Cognitive Associative Therapeutical Society (CATS).

How would the brain synchronize its internal clock without inputs?

Skin. Is the biggest organ and lots of "sensors".

Yeah, these articles are missing the big picture. I've seen too many people cite articles like this while implying effectively that sleep and wakefulness somehow is not related to lighting at all, and that's utter nonsense.

Lighting is VERY relevant to sleep cycles, and there's no doubts about this anywhere legitimate. The most effective is to not ONLY use red-tint in display controls but also have dim indoor lighting AND dark red glasses (darker and redder than even the generic blue-blocking sort). And the effective is dramatic. Like really get sleepy with dim light. It's not subtle, it's about as strong as an effect can be.

Studying merely the question of whether a little more or little less blue affects eye health in terms of serious diagnosable eye conditions is completely missing the point.

We have a hard time remembering that humans used to live outside, all the time, 24/7, every day. With bright moonlight, early sun rise and late sun set. Along with being near active fires. It's going to take a lot of research to convince me humans just never adapted to light for sleep.

In my own observation and experience, the blue light from my notebook at night is most definitely and beyond all doubt hurtful to the quality of my sleep afterwards. No study or scientist could ever convince me otherwise. So headline seems fishy at least.

I have ADHD with some overlap to the spectrum. As a result I am sensitive for light, sounds, things in my viewport. The blue light filter is always active on my phone and in evenings also on my computer screens. It definitely helps me in feeling tired and sleepy earlier in comparison with working without the filter.

I am not familiar with research about this subject. It is possible that blue light is not the reason but maybe the combination of the amber/red glow with a dimmed brightness. However, the blue light filter works very well for me.

I found a study within a few seconds on Google Scholar which refutes OP's study.

Using google translate, i see this in the article (German translated to English):

"According to a recent study, contact lenses that block blue light do not provide better protection from eye fatigue than standard contact lenses than standard contact lenses (American Journal of Ophthalmology 2021; DOI: 10.1016 / j.ajo.2021.02.010), according to the DOG."

Hmm... One article versus several:

https://scholar.google.com/scholar?hl=en&as_sdt=0%2C44&q=blu...

Several studies available at link above. Here's an example from what I found via google scholar query:

"All light is not equal: blue wavelengths are the most potent portion of the visible electromagnetic spectrum for circadian regulation. Therefore, blocking blue light could create a form of physiologic darkness. "

"At the end of the study, the amber lens group experienced significant (p < .001) improvement in sleep quality relative to the control group and positive affect (p = .005). Mood also improved significantly relative to controls. A replication with more detailed data on the subjects' circadian baseline and objective outcome measures is warranted."

[1] https://www.tandfonline.com/doi/abs/10.3109/0742052090352371...

It made very little sense that something we should've been well-adapted to is... dangerous. Even if blue light is not natural at night, why would I want to block it during the day?! I have to spend an enormous effort to let LensCrafters know that I am NOT interested in their gimmicky blue light filter lenses! In fact, bright blue light is essential for good sight and is speculated to be the reason so many kids are shortsighted nowadays!

To be clear, UV and blue light ABSENCE might be the case why so many kids are shortsighted.

What about UV and oxygen? We are well-adapted to those, but over time they degrade our bodies.

The gimmicky glasses barely stop any blue light at all.

The effect of bright blue light on preventing myopia settles down once you reach adulthood. There's no evidence it helps after that, your corneas have already set.

So, we should cut off oxygen, because like everything, it has a beneficial range? I don't mind wearing blue-light-blocking eyeglasses at night, but to wear them all day long is plain stupid. Also, there's the phenomenon called hormesis, which recently shows benefits in the right amounts of even X-ray radiation. So, just like with UV, you should get enough of UV, but not above the upper limit, and should not fall below the lower one either. Same applies to everything including water - too much of it is toxic.

> Same applies to everything including water - too much of it is toxic.

Yes, that was my whole point.

Obviously you can't really reduce oxygen exposure (you can increase it, which is deleterious in high doses), but reduced intake of antioxidants, namely things like methionine and certain vitamins, absolutely does lead to faster degradation of the body. Note: there isn't conclusive evidence more antioxidants is better, just that deficits are definitely bad.

Yeah, antioxidants actually erase the benefits of exercise... which benefits could be speculated to be a results of the controlled oxidative stress.

The same principle of hormesis applies to organic arsenic and many others natural to our diet toxins. Some of the phytochemicals are toxins and anti-nutrients the plans use to fend off herbivores, but could be beneficial to us in the right amounts during the rate state. Our retina has receptors for blue light, which get triggered even when your eyelids are shut. So, do you think blue light is not interesting to our body? Don't you think without bright light your eyesight can develop properly? This is not much different than the hygiene hypothesis - something could be beneficial in the way that we're programmed to expect it, and when we don't get it, our primed defenses actually hurt us. With time, we will adapt to be fine without blue light during the day, without UV, but so far, it seems that we need it for proper development!

I get so frustrated when this topic comes up.

If you have an OLED phone running Android, you can get cf.lumen and use it to turn all blue light off. This uses only red light and preserves night vision and eliminates eye strain. That alone should give intuitive evidence that maybe blue light actually is a danger to our eyes and to our sleep.

But as usual, the phone developer DONT GET IT and continue to not offer this feature as a default even though any OLED can do it.

Money quote:

> Entwarnung gibt DOG-Experte auch in Bezug auf mögliche Schlafstörungen, die das Blaulicht durch abendliches Lesen an elektronischen Geräten verursachen könnte. Auch diese Annahme sei inzwischen durch eine Studie widerlegt (Sleep Health 2021; DOI: 10.1016/j.sleh.2021.03.005). Bach empfiehlt daher, beim Lesen auf einem elektronischen Gerät vor dem Einschlafen lediglich eine maximale Helligkeit des Displays zu vermeiden.

> Der DOG-Präsident Hagen Thieme findet es wichtig, diese Forschungserkenntnisse in die breite Öffentlichkeit zu tragen. „Sie dienen der Aufklärung und schützen Verbraucher vor irreführender Werbung und verunsichernden Falschmeldungen, die rein kommerzielle Interessen verfolgen“, sagte der Direktor der Universitätsaugenklinik Magdeburg.

Translation by deepl.com:

> The DOG expert also gives the all-clear with regard to possible sleep disturbances that the blue light could cause by reading on electronic devices in the evening. This assumption has now also been refuted by a study (Sleep Health 2021; DOI: 10.1016/j.sleh.2021.03.005). Bach therefore recommends simply avoiding maximum display brightness when reading on an electronic device before falling asleep.

> DOG President Hagen Thieme thinks it is important to bring these research findings to the general public. "They serve to educate and protect consumers from misleading advertising and unsettling false reports that pursue purely commercial interests," said the director of the University Eye Hospital in Magdeburg.

To spell it out directly, this says things like f.lux are snake oil. No better than crystals against WiFi "pollution" and suchlike…

Nocturne is my preferred option, particularly if you have other people nearby sleeping (e.g. college roommates). And you will definitely get sleepy with this setup.

https://www.reddit.com/r/macapps/comments/q4yisa/nocturne_be...

This is amazing. Do you know if there's anything similar for Windows and Linux? I know there's flux, but you can't even go this extreme with flux.

I know flux is more limited, but you can turn it to a preset, and then select > Effects & Extra Colors > Himalayan Salt Lamp (which is my preferred option for late night.

Also, you can select Use Wider Slider Ranges in the options to go from 1200k-9300k

I have noticed that Flux on OS X is lacking some of the functionality from the Windows version too.

On Ubuntu it used to be possible to evoke this with changes to color temperature of the night light setting. But, the range has been reduced in recent versions and there isn't any obvious way to set it back.

Andrew Huberman goes to great extent explaining the effects of pretty much everything related to neurobiology, here he talks about blue light and how it affects sleep. https://www.youtube.com/watch?v=nm1TxQj9IsQ&t=1970s

Also a great science based podcast.

edit: context

I was having horrific migraines triggered by light. 5 minutes was sufficient to turn me into a mess.

Glasses with blue light filter helped some if all lights but computer are off.

Fl-41 glasses that covered side and tops would give me hours of normal functioning.

Eventuality got migraines mostly under control, I can go to the store without them for for a hour or two most of the time.

How have you gotten your migraines under control?

Vit d,e,b complex. Magnesium, bob and Brad YouTube videos. Specifically TMj video, but all stretching videos. Massage gun. I switched to an autoimmune protocol diet. Did an elimination diet to find my food triggers.

I don't trust this as this study is very weak and takes into account only a particular platform.

Without blue light filter, after prolongated usage, my eyes start to water and itch. It makes me very uncomfortable.

But with blue light filters like flux and Qredshift, I use dimming and filtering 24/7.

I never have aforesaid problems when I am using filters and dimming.

I have also started to use ambient lighting (just a $4 table lamp) behind the screen. This makes things better.

So, with the lowest brightness allowed with no filters or dimming, I start to face unavoidable peoblems after about four hours of usage.

OTOH, with 24/7 use of flux or qredshift, I can comfortably undergo screen time for 14-15 hours.

I would also like to mention that I have seen difference in being able to sleep.

I've used flux and similar apps for a long time but I've always been annoyed by the lofty claims. It changes the color of your screen, that's good enough, they don't have to act like they're going to turn our lives around.

My dermatologist insists screen light causes skin damage given the number of hours I'm at the computer. I'm skeptical but on her request added a UV blocker as daily care instead of only before going outside. Recent treatment has improved my skin and I'm interested to maintain it but am not sure if wearing sunblock for screen is just a waste of time. Research suggests it is neglible but then again, my skin is sensitive so what's the harm I figure.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6280109/

Look more deeply into the quality of sunblock. Long term daily wear can be a risk for bioaccumulation depending on the type of sunscreen. Most sunscreen has not been investigated by the FDA iirc.

For fun, I suggest getting some blue light blocking glasses - only a couple dollars - and wearing them a couple hours before bed.

Before you get in bed, look at a screen / light. Then take them off. For me, it wakes me right up.

I don't know where this will eventually lead. I tried blue-blocking glasses, but I found simply remembering to adjust my screen's brightness and contrast when the room is dimly lit helped greatly with eye strain. I can't speak to sleep, since I have always lived off of five hours a night, since I was 11 or 12 years old, pre-screen era and steeped deep in screens now. I do set my terminal colors to be the same as my Commodore PET 2001 back in 1977 to an amber on black arrangement. The other PET had the lime, or bright green font.

The paper is about blue light blocking lenses: https://pubmed.ncbi.nlm.nih.gov/33587901/

Here's something to consider. The cells that affect sleep are in such direction that the light coming from overhead has highest effect on it. Oh. And about using phones or computers close to night time, its not necessarily about the light. If you have too much mental or emotional stimulation near sleep time that would definitely harm your ability to sleep. And by mental stimulation, it definitely includes games where being few milliseconds slower means dying in the game.

On the completely different topic, I do not know why people asking why is there so much mistrust in authorities (politics, media, science)...

One day "coffee is good for you health", next day "coffee is bad for you"...

"fats are bad" next day "fats are good for you"

"microwaves are bad" > "microwaves are harmless"

"blue light is bad" > "blue light is ok"

"covid is just a flu" > "run for your life..." > "we can live with covid" ...

We make new discoveries as time progresses. One experiment is set up and it’s results interpreted differently than another.

Now I don’t mind this and choose to believe the most recent credible findings. But I do understand when people see this as flip-flopping or maybe even contradicting.

I don’t like to admit it, but I also understand why that doesn’t particularly bolster trust.

I do not doubt scientific method, I doubt people's ability to carry out scientific method correctly and without bias and agenda.

Relative number of lies/media sensation is inversely proportional with trust. Solution, reduce corruption, sensational news and lies.

Note: Sorry about unrelated root topic, I remembered a scientist attending "Global Challenge Competition" asking "Why people nowadays more and more mistrust authorities..."

None of those statements are scientific and scientists don't talk like that, so the onus falls squarely on politics and media. And laypeople. People consume a ton of knowledge from their peers, even before social media.

Each of those points has enough nuance to fill volumes of research papers.

Regardless of side-effects (no idea what to believe anymore)... I've found that using the automatic colour temperature adjustment programs to make using computer screens in the evening feel less out of place. Even ignoring natural light, we tend to use warm lighting indoors, and when the day is done 6500k just looks blue in this context due my eyes adjusting to the environment.

I set and forgot redshift in my xinitrc a few years ago and now it always looks right.

https://www.androidauthority.com/blue-light-filters-1067108/

also, google Google integrated a blue light filter into older versions of Android such as Oreo.

When I saw this headline I just knew what we would find in the comments.

The reaction on hacker news is basically the same as you will get from someone who uses homeopathy being confronted with a study that says it doesn't work.

If you use something day-to-day it becomes part of your identity. It doesn't matter what some scientist says. It doesn't matter what anyone says. "It helps me so I'm going to keep doing it".

I agree that looking at HN when a study proves/disproves something is a funny case study on confirmation bias but likewise just blindly accepting the conclusions of a study is also wrong.

In reality I think for the average person it's most useful to completely ignore all studies they encounter until they are presented with a meta-analysis (at least) and the inputs of at least a few knowledgeable scientists on the interpretation of said meta-analysis.

Science is really fuzzy, especially when a topic is under-studied, trusting/distrusting a single study just on the basis of one study, based on some anecdotes or even based on an observation that people are being biased against it is bad in general.

Is that supposed to be a bad thing? If the relief feels real to a person and they aren’t actively harming themselves with their preferred treatment (possibly also by avoiding a better treatment) then what’s the difference?

And when I saw that article I immediately recalled all bogus "research", that indicated that ionized radiation is harmless (sure thing, buddy) or that various carcinogens (currently proven to be carcinogenic) are actually good for one's health.

Billions of people have been using computers for decades. They are not going blind. There is no epidemic of insomnia. At the same time, there are thousands, who claim, that looking at monitor with adjusted gamma feels more pleasing and helps their sleep. Why are they saying so?

Instead of studying the actual phenomena (different monitor gamma acting as signal to sleep) the "researchers" went out of they way to confirm something, their sponsors wanted them to confirm. Circadian rhythms? Nah, never heard about those — let's just check for retina damage and eye strain after brief 2hr period.

When I saw that, my first question for myself was

"Is this the placebo effect in practice?"

I use Flux @3400k at night, which I then set to Himalayan Salt Lamp also, to make me ready for bed, and my perception is that I experience less eye strain, and more feeling ready to go to sleep.

I'm going to need to read more studies on this...

At this point, blue light glasses/warm, low-brightness screens are a preference. I have 20/20 vision and get 8 hours of sleep, but my eyes can't handle constant blue light anyway.

Everyone trying to sleep with lights on knows that bright light definitely hinders sleep. This is even used to torture people. The spectrum of the light is most probably only a secondary effect.

The sleep part definitely doesn’t line up with my experience.

“Or sleep” isn’t true for me. I can’t sleep unless f.lux is on. QuickShade is also great, since the minimum brightness is still way too bright.

I never understood why blue light is supposed to be a problem. Surely on a sunny day with blue sky there is a lot of blue light?

Folks will vigorously defend their placebos, especially if there's no downside. In fact, their placebo is working.

Content from monitors, ie information carried by monitor blue light, maybe a danger to eyes or sleep. :)

It makes your eyes tired so you start rubbing them and that might cause trouble for some!

TL;DR: just lower your display brightness.

I'd like to provide my opinion based on some observations:

First, human eyes have probably evolved to work in natural daylight. This corresponds to [CIE D65][1] standard, which "is intended to represent average daylight and has a correlated colour temperature of approximately 6500 K".

Second, the other common recent trend is dark theme everything.

The common cause for these seems to be an excessive brightness. My simple rule is a screen filled with white should not cause eye discomfort. That's it. Lowering color temperature and switching to a dark theme are different means to a common goal of lowering overall display brightness. Warmer colors are perceived as softer and less bright. Dark theme is an overengineered way to make display darker.

I believe the "blue color danger" is/was an artificially inflated hype to sell browser/os extensions. Since most OS nowadays have color temp controls built in, unaffiliated research started to emerge.

[1]: https://en.wikipedia.org/wiki/Illuminant_D65

Why is a dark theme "overengineered?" You can't just arbitrarily turn down the brightness of a screen and still be able to read it. There's a minimum level of contrast required. Dark themes retain that minimum level while still greatly reducing overall brightness.

Developing a whole new UI theme instead of just turning brightness down is what I call an overengineered solution (to a problem that barely exists)

The problem is real for people with disabilities.

This site is garbage. I downloaded the article and the only mention of blue light and sleep is "the authors concluded that high-quality clinical trials are required to achieve clarity". As for their claims of blue light blocking, read their limitations section.

Looks like no phone was the best for sleep, no surprises there

No issues...get back to work...nothing to see hear, move along folks.

Blue light protection glasses a danger to hip-pocket.

Author gonna get sued by BLUBlox

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