23 ms·

Blue light from monitors no danger to eyes or sleep

376 points by _gfwu 5y ago

Lamad123 5y ago
It makes your eyes tired so you start rubbing them and that might cause trouble for some!
Havoc 5y ago
The sleep part definitely doesn’t line up with my experience.
mahathu 5y ago
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/ https://pubmed.ncbi.nlm.nih.gov/33587901/
- robarr 5y ago
  Off-topic: deepl, in my experience, is a much accurate/nuanced translator than Google/Microsoft.
  - CarVac 5y ago
    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-machine-learning-tool-pulse-stylegan-obama-bias https://www.theverge.com/21298762/face-depixelizer-ai-machin...
- ImaCake 5y ago
  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.
  - ImaCake 5y ago
    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.
  - kortex 5y ago
    I don't know why you are being downvoted, this is 100% correct. It's the whole reason we do things like power analysis.
    - ImaCake 5y ago
      Thanks, I am glad to know my half finished Masters degree isn’t a total waste :)
- pvg 5y ago
0x000000001 5y ago
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
- Mountain_Skies 5y ago
  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.
  - generalizations 5y ago
    Blue light carries the most energy, so I imagine filtering it out has the greatest effect compared to those other mitigations.
    - ekianjo 5y ago
      What do you mean by the most energy ?
      - kortex 5y ago
        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.
        ekianjo 5y ago
        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~.
jml7c5 5y ago
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_retinal_ganglion_cell https://en.wikipedia.org/wiki/Intrinsically_photosensitive_r...
- dimitrios1 5y ago
  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.
  - jml7c5 5y ago
    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-ophthalmology https://www.eophtha.com/posts/fun-with-prisms-in-ophthalmolo...
cududa 5y ago
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?
- draw_down 5y ago
  Trust the science! :)
- jazzyjackson 5y ago
  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.
  - hellbannedguy 5y ago
    I'm glad they at least tried to please customers. I just figured they still used florescent.
asdff 5y ago
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.
- TaylorAlexander 5y ago
  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.
  - ImaCake 5y ago
    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.
    - epberry 5y ago
      I agree. https://github.com/jonls/redshift 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.
    - GhettoComputers 5y ago
      Is that only because it’s bright and contrasts strongly with the darkness? A dim one without a color filter looks fine to me.
      - TaylorAlexander 5y ago
        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.
kgarten 5y ago
The paper is about blue light blocking lenses: https://pubmed.ncbi.nlm.nih.gov/33587901/ https://pubmed.ncbi.nlm.nih.gov/33587901/
sillysaurusx 5y ago
“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.
Waterluvian 5y ago
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.
jcrben 5y ago
Looks like no phone was the best for sleep, no surprises there
throwaway803453 5y ago
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.
- toomuchtodo 5y ago
  https://academic.oup.com/biomedgerontology/article/75/9/e49/5863431 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
  - DantesKite 5y ago
    Very interesting. Thank you. Red light is also just fun to be in. It has a different atmospheric mood.
    - blackhaz 5y ago
      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.
  - jml7c5 5y ago
killjoywashere 5y ago
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_best_extreme_nightvision_option_of_any/ https://www.reddit.com/r/macapps/comments/q4yisa/nocturne_be...
- ajdude 5y ago
  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.
  - OrvalWintermute 5y ago
    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.
  - inciampati 5y ago
    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.
Negitivefrags 5y ago
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".
- Arch-TK 5y ago
  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.
- Lammy 5y ago
  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?
- altfredd 5y ago
  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.
wombatmobile 5y ago
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).
- inciampati 5y ago
  How would the brain synchronize its internal clock without inputs?
  - ccozan 5y ago
    Skin. Is the biggest organ and lots of "sensors".
bscphil 5y ago
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 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.
- lima 5y ago
  > 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.
  - bscphil 5y ago
    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.
- 5y ago
zz865 5y ago
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?
devwastaken 5y ago
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.
vlunkr 5y ago
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.
nikolay 5y ago
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!
- copperx 5y ago
  To be clear, UV and blue light ABSENCE might be the case why so many kids are shortsighted.
- kortex 5y ago
  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.
  - nikolay 5y ago
    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.
    - kortex 5y ago
      > 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.
alexeiz 5y ago
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.
- ncmncm 5y ago
  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.
esalman 5y ago
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.
winrid 5y ago
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.
fellellor 5y ago
Content from monitors, ie information carried by monitor blue light, maybe a danger to eyes or sleep. :)
yosito 5y ago
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.
NiceWayToDoIT 5y ago
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" ...
- pindab0ter 5y ago
  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.
  - NiceWayToDoIT 5y ago
    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..."
- kortex 5y ago
  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.
decide1000 5y ago
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.
josmala 5y ago
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.
treeman79 5y ago
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.
- hutrdvnj 5y ago
  How have you gotten your migraines under control?
  - treeman79 5y ago
    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.
telesilla 5y ago
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/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6280109/
- nostrebored 5y ago
  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.
amai 5y ago
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.
lysp 5y ago
Blue light protection glasses a danger to hip-pocket.
kiryin 5y ago
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.
- jacobmischka 5y ago
  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.
  - kasabali 5y ago
    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.
- webmobdev 5y ago
  That has been my experience too. Using an app like Flux https://justgetflux.com/ 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".
tomxor 5y ago
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.
lima 5y ago
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/S2352721821000607 https://www.sciencedirect.com/science/article/abs/pii/S23527...
- DeusExMachina 5y ago
  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/ https://justgetflux.com/news/pages/macquickstart/ [2] https://justgetflux.com/research.html https://justgetflux.com/research.html
  - dijit 5y ago
    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/ https://bluelightatnight.com/the-problem-with-flux/
    - Der_Einzige 5y ago
      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.
jdthedisciple 5y ago
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.
KronisLV 5y ago
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/ https://justgetflux.com/ and something like Redshift https://help.ubuntu.com/community/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.
- spurgu 5y ago
  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!
- avianlyric 5y ago
  > 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.
mabil 5y ago
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 https://www.youtube.com/watch?v=nm1TxQj9IsQ&t=1970s Also a great science based podcast. edit: context
Der_Einzige 5y ago
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.
twistedpair 5y ago
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.
- bamboozled 5y ago
  Did you mean 1am?
- kzrdude 5y ago
  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.
- jwond 5y ago
  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.
flerchin 5y ago
Folks will vigorously defend their placebos, especially if there's no downside. In fact, their placebo is working.
cabirum 5y ago
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 https://en.wikipedia.org/wiki/Illuminant_D65
- virgil_disgr4ce 5y ago
  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.
  - cabirum 5y ago
    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)
    - antifa 5y ago
      The problem is real for people with disabilities.
eggy 5y ago
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.
xlaacid 5y ago
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.
datavirtue 5y ago
No issues...get back to work...nothing to see hear, move along folks.
sequel_database 5y ago
Author gonna get sued by BLUBlox
quadrangle 5y ago
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.
vesuvianvenus 5y ago
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=blue+light+sleep 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/10.3109/07420520903523719 https://www.tandfonline.com/doi/abs/10.3109/0742052090352371...
still_grokking 5y ago
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…
16Sinker 5y ago
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.
rg111 5y ago
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.
mito88 5y ago
https://www.androidauthority.com/blue-light-filters-1067108/ https://www.androidauthority.com/blue-light-filters-1067108/ also, google Google integrated a blue light filter into older versions of Android such as Oreo.

376 points by _gfwu 5y ago

Lamad123 5y ago

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

Havoc 5y ago

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

mahathu 5y ago

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

robarr 5y ago
Off-topic: deepl, in my experience, is a much accurate/nuanced translator than Google/Microsoft.
- CarVac 5y ago
  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-machine-learning-tool-pulse-stylegan-obama-bias https://www.theverge.com/21298762/face-depixelizer-ai-machin...
ImaCake 5y ago
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.
- ImaCake 5y ago
  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.
- kortex 5y ago
  I don't know why you are being downvoted, this is 100% correct. It's the whole reason we do things like power analysis.
  - ImaCake 5y ago
    Thanks, I am glad to know my half finished Masters degree isn’t a total waste :)
pvg 5y ago

0x000000001 5y ago

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

Mountain_Skies 5y ago
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.
- generalizations 5y ago
  Blue light carries the most energy, so I imagine filtering it out has the greatest effect compared to those other mitigations.
  - ekianjo 5y ago
    What do you mean by the most energy ?
    - kortex 5y ago
      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.
      - ekianjo 5y ago
        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~.

jml7c5 5y ago

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_retinal_ganglion_cell https://en.wikipedia.org/wiki/Intrinsically_photosensitive_r...

dimitrios1 5y ago
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.
- jml7c5 5y ago
  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-ophthalmology https://www.eophtha.com/posts/fun-with-prisms-in-ophthalmolo...

cududa 5y ago

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?

draw_down 5y ago
Trust the science! :)
jazzyjackson 5y ago
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.
- hellbannedguy 5y ago
  I'm glad they at least tried to please customers. I just figured they still used florescent.

asdff 5y ago

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.

TaylorAlexander 5y ago
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.
- ImaCake 5y ago
  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.
  - epberry 5y ago
    I agree. https://github.com/jonls/redshift 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.
  - GhettoComputers 5y ago
    Is that only because it’s bright and contrasts strongly with the darkness? A dim one without a color filter looks fine to me.
    - TaylorAlexander 5y ago
      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.

kgarten 5y ago

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

sillysaurusx 5y ago

“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.

Waterluvian 5y ago

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.

jcrben 5y ago

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

throwaway803453 5y ago

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.

toomuchtodo 5y ago
https://academic.oup.com/biomedgerontology/article/75/9/e49/5863431 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
- DantesKite 5y ago
  Very interesting. Thank you. Red light is also just fun to be in. It has a different atmospheric mood.
  - blackhaz 5y ago
    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.
- jml7c5 5y ago

killjoywashere 5y ago

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

ajdude 5y ago
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.
- OrvalWintermute 5y ago
  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.
- inciampati 5y ago
  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.

Negitivefrags 5y ago

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".

Arch-TK 5y ago
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.
Lammy 5y ago
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?
altfredd 5y ago
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.

wombatmobile 5y ago

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).

inciampati 5y ago
How would the brain synchronize its internal clock without inputs?
- ccozan 5y ago
  Skin. Is the biggest organ and lots of "sensors".

bscphil 5y ago

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 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.

lima 5y ago
> 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.
- bscphil 5y ago
  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.
5y ago

zz865 5y ago

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?

devwastaken 5y ago

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.

vlunkr 5y ago

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.

nikolay 5y ago

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!

copperx 5y ago
To be clear, UV and blue light ABSENCE might be the case why so many kids are shortsighted.
kortex 5y ago
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.
- nikolay 5y ago
  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.
  - kortex 5y ago
    > 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.

alexeiz 5y ago

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.

ncmncm 5y ago
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.

esalman 5y ago

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.

winrid 5y ago

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.

fellellor 5y ago

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

yosito 5y ago

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.

NiceWayToDoIT 5y ago

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" ...

pindab0ter 5y ago
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.
- NiceWayToDoIT 5y ago
  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..."
kortex 5y ago
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.

decide1000 5y ago

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.

josmala 5y ago

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.

treeman79 5y ago

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.

hutrdvnj 5y ago
How have you gotten your migraines under control?
- treeman79 5y ago
  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.

telesilla 5y ago

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

nostrebored 5y ago
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.

amai 5y ago

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.

lysp 5y ago

Blue light protection glasses a danger to hip-pocket.

kiryin 5y ago

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.

jacobmischka 5y ago
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.
- kasabali 5y ago
  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.
webmobdev 5y ago
That has been my experience too. Using an app like Flux https://justgetflux.com/ 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".

tomxor 5y ago

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.

lima 5y ago

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/S2352721821000607 https://www.sciencedirect.com/science/article/abs/pii/S23527...

DeusExMachina 5y ago
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/ https://justgetflux.com/news/pages/macquickstart/ [2] https://justgetflux.com/research.html https://justgetflux.com/research.html
- dijit 5y ago
  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/ https://bluelightatnight.com/the-problem-with-flux/
  - Der_Einzige 5y ago
    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.

jdthedisciple 5y ago

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.

KronisLV 5y ago

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/ https://justgetflux.com/ and something like Redshift https://help.ubuntu.com/community/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.

spurgu 5y ago
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!
avianlyric 5y ago
> 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.

mabil 5y ago

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 https://www.youtube.com/watch?v=nm1TxQj9IsQ&t=1970s Also a great science based podcast. edit: context

Der_Einzige 5y ago

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.

twistedpair 5y ago

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.

bamboozled 5y ago
Did you mean 1am?
kzrdude 5y ago
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.
jwond 5y ago
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.

flerchin 5y ago

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

cabirum 5y ago

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 https://en.wikipedia.org/wiki/Illuminant_D65

virgil_disgr4ce 5y ago
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.
- cabirum 5y ago
  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)
  - antifa 5y ago
    The problem is real for people with disabilities.

eggy 5y ago

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.

xlaacid 5y ago

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.

datavirtue 5y ago

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

sequel_database 5y ago

Author gonna get sued by BLUBlox

quadrangle 5y ago

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.

vesuvianvenus 5y ago

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=blue+light+sleep 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/10.3109/07420520903523719 https://www.tandfonline.com/doi/abs/10.3109/0742052090352371...

still_grokking 5y ago

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…

16Sinker 5y ago

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.

rg111 5y ago

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.

mito88 5y ago

https://www.androidauthority.com/blue-light-filters-1067108/ https://www.androidauthority.com/blue-light-filters-1067108/ also, google Google integrated a blue light filter into older versions of Android such as Oreo.