There’s a lot to learn about how blue light affects our eyes

(f.lux author here): the initial part of this press cycle was effectively scare-mongering, and was later mostly retracted by Karunarathne. See <a href="https:&#x2F;&#x2F;www.theverge.com&#x2F;2018&#x2F;8&#x2F;17&#x2F;17724658&#x2F;screen-time-blue-light-blindness-science" rel="nofollow">https:&#x2F;&#x2F;www.theverge.com&#x2F;2018&#x2F;8&#x2F;17&#x2F;17724658&#x2F;screen-time-blue...</a><p>This (older) article says: &quot;we don&#x27;t spend that much time staring at the sun&quot;. But just seeing the blue sky gives your retina about 50x the dose of blue light (hazard) as a normal LED display.<p>Blue light hazard is generally considered to be &quot;reciprocal&quot; which means for most doses, you can measure total energy (power * time). So it is easy to argue that one hour spent outdoors (<i>not</i> staring at the sun, just doing normal stuff) gives you more dose than 12 hours at a computer. So for light seen during the day, nobody has yet shown that seeing a computer is harmful, and the risk should be lower than spending an hour outdoors.<p>At night, it&#x27;s another story, and there is not clear evidence here. The retina experiences daily circadian rhythms, and so risks to your eye may be enhanced by bright light seen at night. Less light at night is good for your circadian clock, and it is almost certainly good for your eyes too.

Lots more information about this in Richard Feynman’s Color Vision lecture:<p><a href="http:&#x2F;&#x2F;www.feynmanlectures.caltech.edu&#x2F;I_35.html" rel="nofollow">http:&#x2F;&#x2F;www.feynmanlectures.caltech.edu&#x2F;I_35.html</a>

Android 9, and maybe 8 but I never checked, offers an opacity setting.<p>I leave the filter on, and the setting to a point where I see an overall display color temp close to the old NTSC value: 6,500k. Being an 80&#x27;s kid, values centered on 6,500 were common. I remember the shift upward becoming more common. It was intense!<p>For people who were viewing during the cooler periods, warmer displays are something one can feel. It is a lot like the feeling one gets when stepping outside after a long, device free, period indoors.<p>A 6,500 ish display temp presents an orange tint when compared to most device defaults seen today. For me, this is almost unnoticeable after a brief time. I adapt quickly and basically become unaware.<p>A nice, darker phone theme helps.<p>I really like the warmer settings, but they do have an impact on me. Sleep and eye fatigue. For most things I find I just do not care and will save a really warm session for a movie, or other special time.

I bought a monitor with a &quot;Low Blue Light&quot; feature built-in. At first I didn&#x27;t use it, but after reading up on it I decided to give it shot. I have three monitors on my desk so I reduced the blue on the other two manually.<p>It was a bit hard to get used to at first, it seemed to make things a bit more green to me, but after about a week I switched it off and it only took a few minutes to notice the difference. My eyes felt a lot more strained with it turned off.<p>If I were doing graphic work I suppose I&#x27;d have to turn it off, but I&#x27;m not so I don&#x27;t worry much about how it effects the little bit of UI work I do.

Mentioning Flux - a free blue light reducing app that is beautiful and functional - as I’m always surprised how many people haven’t heard of it.<p>Takes exactly 5 mins to get used to it and after working with flux on I’m amazed how overwhelming default monitor settings feel.<p><a href="https:&#x2F;&#x2F;justgetflux.com&#x2F;" rel="nofollow">https:&#x2F;&#x2F;justgetflux.com&#x2F;</a>

&quot;But ophthalmologists aren’t worried. The blue light emanating from the sun drastically overpowers any rays coming from your screen. And so far, all of the research on how real human eyes react to blue light has failed to link screens to permanent damage of any kind. Blue light’s most concerning effects still seems limited to sleeplessness.&quot;<p>OK, so what else is there to learn?

My normal glasses have the blue light filter, not my sunglasses though.