
There’s a lot to learn about how blue light affects our eyes - ALee
https://www.popsci.com/screens-killing-eyes-blue-light
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herf
(f.lux author here): the initial part of this press cycle was effectively
scare-mongering, and was later mostly retracted by Karunarathne. See
[https://www.theverge.com/2018/8/17/17724658/screen-time-
blue...](https://www.theverge.com/2018/8/17/17724658/screen-time-blue-light-
blindness-science)

This (older) article says: "we don't spend that much time staring at the sun".
But just seeing the blue sky gives your retina about 50x the dose of blue
light (hazard) as a normal LED display.

Blue light hazard is generally considered to be "reciprocal" which means for
most doses, you can measure total energy (power * time). So it is easy to
argue that one hour spent outdoors ( _not_ 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.

At night, it'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.

~~~
teamski
OT: I used flux ages ago. You seem still to be active since you intro'd
yourself als the flux guy. Out of curiosity, why should anyone still use flux
nowadays when all OSes have time-based red-shifting built-in?

~~~
Mountain_Skies
A greater deal of blue filtering was available on f.lux last time I used it.
Unfortunately since it did not allow for setting hours other than the local
sunrise and sunset times, it wasn't useful to someone like me that suffers
light exposure insomnia during the months with longer daylight hours. Even
though my home has been setup to accommodate this, f.lux, at least last time I
used it, would not. The built in feature in my OS happily lets me choose for
myself when to filter blue instead of denying me that choice.

~~~
CGamesPlay
It sounds like you've moved on so this likely isn't useful, but f.lux lets you
override the GPS coordinates, so you could likely just negate your latitude to
shift to your location's winter schedule.

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hypertexthero
Lots more information about this in Richard Feynman’s Color Vision lecture:

[http://www.feynmanlectures.caltech.edu/I_35.html](http://www.feynmanlectures.caltech.edu/I_35.html)

~~~
pcl
Wow, I just read the first section (four or five paragraphs) and learned two
new things already. Is this representative of Feynman’s writings? The level of
both clarity and information is impressive.

~~~
kace91
If you haven't yet read Feynman, you're in for a treat. It's not common at all
to find someone with both great domain knowledge and great communication
skills.

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ddingus
Android 9, and maybe 8 but I never checked, offers an opacity setting.

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's kid,
values centered on 6,500 were common. I remember the shift upward becoming
more common. It was intense!

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.

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.

A nice, darker phone theme helps.

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.

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oblib
I bought a monitor with a "Low Blue Light" feature built-in. At first I didn'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.

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.

If I were doing graphic work I suppose I'd have to turn it off, but I'm not so
I don't worry much about how it effects the little bit of UI work I do.

~~~
morpheuskafka
Do these monitor features have any advantage over f.lux, Windows/Apple Night
Light, or similar software implementations that work on any monitor?

~~~
smileybarry
Well, for one thing they (at least in ASUS's case) appear to do the opposite
of Night Light / flux by subtracting the blue channel rather than increasing
the red channel. This means at first the image looks a tad green/yellow-er,
but you get used to it much more than Night Light's red tint. I've had it for
a year now, mostly on the highest level (certified as "70% blue light
reduction") and I still sometimes check that it's on. (But once you see the
onscreen UI in a blue-ish white it's very obvious)

My eyes also get a lot less fatigued with it on compared to OS features/flux,
even after tuning my monitor & room brightness accordingly with a colorimeter.

A lot of it might come down to certification and blue light reduction methods
at the monitor level. In ASUS's case they claim to be certified by TUV
Rheinland[1].

[1]
[https://www.asus.com/Microsite/display/eye_care_technology/](https://www.asus.com/Microsite/display/eye_care_technology/)

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aresant
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.

Takes exactly 5 mins to get used to it and after working with flux on I’m
amazed how overwhelming default monitor settings feel.

[https://justgetflux.com/](https://justgetflux.com/)

~~~
ksaj
On Windows the pointer remains white so once you get used to the rest of the
screen (a few minutes the first time, and pretty much instantaneous
thereafter), the pointer appears to take on this very potent blue. Switching
flux off at this point is damn near blinding, so it is definitely having a
profound effect.

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Ace17
"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."

OK, so what else is there to learn?

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Freestyler_3
My normal glasses have the blue light filter, not my sunglasses though.

