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> To protect your eyes from blue light, Karunarathne advises to [...] avoid looking at your cell phones or tablets in the dark.
Can someone explain why it would be worse to look at a cell phone in the dark? It's emitting the same blue light (or less, if the display gets dimmer) as it is in a bright environment. Why is that light more harmful in a dark environment?
I use f.lux all day I don't know if I'm particularly sensitive or if it's all in my head but when I turn off f.lux, especially at night, to watch some movie or video I can physically feel my pupils dilate and it almost feels like my eyes go from being at rest to being strained.
I'm in the process of building a Philips Hue-compatible light therapy LED strip that goes above my bed, and I chose 500 nm cyan LEDs due to this concern. The goal is to have the lights gradually wake me up every morning and help align my sleep cycles, as I suffer from Delayed Phase Sleep Disorder.
Figure 3[0] in the paper seems to show that 500 nm is safe, and that melanopsin has high absorption at 500nm, which has important effects on circadian rhythm[1].
Anyone more knowledgable than me know if this setup is safe?
In addition to f.lux, I also use the Dark Reader Chrome extension[1], which dynamically generates dark themes for every page you visit. It seems to make a bigger difference than using f.lux.
I don't quite understand. Blue light - any blue light - causes blindness? So we shouldn't look at the sky even?
I've never heard blue being a danger other than its effect on the biological clock, so that seems like a pretty bold claim. Ultraviolet, sure...
Though buried in there is something about immune system and vitamin E levels...
I really find it hard to believe that blue light exposure is automatically bad. We have receptors for that specific purpose. Wearing blue light filtering sunglasses all the time as the article suggestions seems a bit ridiculous. Why give up one color entirely?
One solution I use is a 1/8" thick sheet of amber transparent rigid plastic/acrylic. It is designed to cut UV, but it also cuts blue light. I bought a 2'x4' sheet from an online site (since ads are probably not permitted, I will not mention the name of the company), and they cut it to size specifications for me. Out of that I got filters for my 14", 15" and 17" laptops, and a 30" LED TV.
I find it easier on my eyes at night (both laptop and TV), and it has its place since the TV can't run f.lux and redshift.
Note that the lens of the eye yellows as you get older which significantly reduces the amount of blue light that reaches the retina. So much so that there is an idea floating around that older people don't get enough blue light to properly make the circadian stuff work and that teenagers get too much.
I was recently diagnosed with a condition called retinitis pigmentosa (it basically just destroys your retinas). It's part of a larger condition called usher syndrome (which caused my severe hearing loss at birth). I'm on heavy doses of vitamin a palmitate as well as some other vitamins. Another thing that I haven't done yet but will be doing shortly is blue light blocking glasses, especially since I sit in front of a computer all day. I also use f.lux and night shift on windows and mac respectively. I'm 22 and have lost a significant portion of my night and peripheral vision so I'm still just trying to figure this all out. Any tips are welcome.
I deeply hate blue leds, never liked them. As an electronics hobbyist I have been used for many years to the old red then green and yellow leds before the blue and later white ones came out, so I rushed out to buy some as soon as I could and while trying them I remember feeling uncomfortable staring at that light, to the point I never used them in anything: they're staying in their box for good. I already know about the blue light altering the circadian rhythm, but didn't back then, so it's possible the brain was sending a message there was something wrong with that light.
f.lux author here, still slogging through the article. It is hard to understand the light levels used because they use "power" (uW, mW) from a laser, and not "irradiance" (uW/cm^2 or mW/cm^2), so which area they have concentrated that light over is hard to understand. All I can see is it is from a laser, so the irradiance could be extremely high.
The human lens filters most light at the peak of the given spectrum for free retinal (383nm), and so once you get to 450nm like an LED, the hazard data in the visual range is 100x less sensitive, see Fig 1 here:
"The researcher found that a molecule called alpha tocoferol, a Vitamin E derivative and a natural antioxidant in the eye and body, stops the cells from dying. However, as a person ages or the immune system is suppressed, people lose the ability to fight against the attack by retinal and blue light."
Does this mean that consuming alpha tocoferol can combat the toxic effect of blue light? If so, at what dosage?
I am excited about LED lights for their efficiency, but keep seeing articles like this and don't understand the practical ramifications, like "what bulbs should I buy?"
Really surprised there's no discussion here about the ubiquitousness of black-on-bright-white color schemes in apps (including this text box I'm typing into right now, though for the most part, HN uses a soft beige tint for its background; but it's still dark-on-light). It's really quite unnecessary. For code editing I have a light-on-dark Emacs color scheme, which is much easier on the eyes.
Yes, Macs have a setting to invert the color palette, but that's not useful to me — a lot of my windows are dark; I don't want them inverted, and it makes images unintelligible. What I really want is something that doesn't screw with images, but detects dark-on-light text and maps the colors in such a way as to preserve contrast and even hue.
Well at least a start is to use software like f.lux that reduces the blue levels on the screen. There are also over screen filters and yellow tinted glasses that can filter the blue light.
Use f.lux or an equivalent (most OS have their own implementation by now) that filters out the blue light at software/rendering level, it's not perfect but you do instantly feel the comfort it brings to your eyes.
Been using f.lux for over 10 years and it also helps alot with going to sleep at night. When it's off your eyes/brain thinks that they are in daytime / broad daylight, when it's on I fall asleep 2 or 3 times faster than without.
I've been wondering if GB-R LED backlit displays help? I haven't seen any reviews which compare the LED spectrum vs a standard white (blue)LED backlit display, but it might be something of interest.
Examples of a GB-R LED backlit display include the NEC PA302W, so they aren't common.
This is not a permanent solution because simply shifting the color temperature has the side effect of generating melatonin and disrupting your circadian clock. You really need a daylight white spectrum and not concentrate all the blue-green energy in one blue spike.
Your pupils are more dilated, due to the surrounding darkness, and hence let more light in. If you were to dim your screen enough to compensate, it would likely be too dark to read.
Because of the way your eyes work.
If it is bright, your pupil will be shrunk, to not be blinded by the luminosity.
When it is dark, your pupil will be opened wide up.
It is this principle that camera apertures are based on.
Now if you have your pupil wide open in a completely dark environment and put a 100% brightness screen at ~10cm of your eyes, what do you expect will happen ?
Our eyes are made for nature, that means day and night, now we have technology that is akin to a handheld sun and you use this at night at 10cm of your face, our eyes are simply not equipped to handle this.
Same - I have flux setup to be active during work hours (at work) and evening hours (at home) so it's filtering blue light on all my devices. When I accidentally close it or turn it off for a movie, I feel like a vampire in sunlight. I have such an easier time falling asleep thanks to flux.
Judging by the relative light intensities of daylight and computer screen light, I would say it will be sufficient to close your eyes for 6 minutes when you are outside on a sunny day to offset 10 hours of computer use.
Maybe dark adaptation can change that, but I haven't found anything about that upon quick unprofessional examination of [0].
Check the spec sheet of the bulbs, specifically the color temperature in kelvin. Ignore the "warm white" and similar marketing terms, they are too fuzzy.
A LED with low color temperature and high CRI should have pretty much the same spectrum as incandescent. If you want really low temperatures look for some retro filament style LED lights.
You can't develop myopia or hyperopia after your eyes/skull/orbital muscles are done growing. So this suggestion probably applies only to adults.
Keep in mind that this is age-related macular degeneration. Your photoreceptor cells are protected by the α-tocopherol until "a person's 50s or 60s." You wouldn't need any prophylactic interventions until then.
I think, white LED bulbs do use a single wavelength blue LED, but they pass it through phosphors which transform it into a similar distribution of wavelength that you would find from an incandescent bulb, or sunlight. LED's are a lot better than fluorescent lighting, which does often have very dramatic peaks and gaps.
In theory, you can look at the CRI rating, but in fact CRI only uses a small number of wavelength probes for the test, so a rating of 100 doesn't necessarily mean a smooth spectrum, it could be the manufacturer has tuned wavelength peaks in order to game the test. There are better rating systems being developed, but they're not used by manufacturers or mandated by governments yet.
I actually think it might be the lightbulbs that change colour which could be problematic. I wouldn't be suprised if some of those did generate the colour just with single wavelength blue, green and red sources. Hopefully the better ones would have individual phosphors for each r/g/b source which produces a spectrum which when combined is reasonable.
I would be particularly careful about cheap/unbranded colour-variable lightbulbs. I doubt they've been through much or any consumer testing, it seems you can buy anything straight off the boat from China through domestic web stores these days.
How does the amount of blue light we see from our computers and mobile devices compare to the blue light seen from the rest of the world quantitatively? While I agree that f.lux helps in the night, I'd guess that the impact caused by f.lux to prevent the effect mentioned in the article is pretty minimal. (Obviously, I have no citations or references; just a wild guess.)
Def'ly a great relief for my eye strain - using it during the day too and keeping on by default.
One annoyance is that Chrome needs to let the address bar be darkened as well as it stands out like a neon tube when Dark Reader is on.
I'm sorry I can't help you, but after reading an article posted here about melatonin I got interested in light therapy, but commercial devices are a bit expensive.
Are you documenting your project?
I remember having serious issues when I was younger with this. It's still sort of a a problem, but I've learned to cope. I'd also be interested if you documented your setup :).
We have chemical receptors on our tongue and in our nose for poisons. We have neurons that detect pain. Just because we can sense it doesn't mean it's not harmful.
It says that your body's normal antioxidants prevent damage. This is only a problem for people who have low levels of alpha tocopherol, e.g. from malnourishment or aging.
2011 was a while ago, this Stack Exchange post from 2013 seems to indicate there is a possibility for macular degeneration with use of these devices, particularly if you are already at risk for the condition:
https://skeptics.stackexchange.com/questions/13891/can-blue-...
Some googling seems to indicate there were rumors of these lights potentially causing issues, and it sounds like the Chemist article may be presenting a scientific basis for that speculation.
I use Night Shift. I'm able to fall asleep minutes after closing my laptop and laying down. For me it's more about comfort than sleep. The blue light is much too bright late at night. My computer no longer hurts my eyes when I stay up late working on cool things.
I've been using F.lux for over seven years. Advantages…
- You have a great deal of control over the blue level. Night Shift's blue level is higher than F.lux's default, and not adjustable.
- Flux transitions more naturally as the sun goes down.
- More scheduling options, "disable until tomorrow".
- the big one: disabling per-app or for full-screen apps. You probably don't want Flux on while watching a movie or binging on a videogame. (I set up my lady friend with Night Shift and watched a movie with her recently, spent the whole film wondering why they made such awful color choices)
Thanks for sharing! I did not know about this. I use Stylus and dark themes for many sites, but this will be great for random sites.
https://add0n.com/stylus.html