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Chemists discover how blue light speeds blindness

phys.org

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Re: Chemists discover how blue light speeds blindness

#171

Post by lphnull »

rgrove wrote: post #41
_nkoa wrote: post #32

Earlier quoted context omitted.

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 m…

Hmm. If I've been in the dark for a while and then pick up my phone, the brightness hurts my eyes for a moment until they adjust to it. When I put the phone down, it takes a moment before I begin to be able to see things in the dark room. Doesn't that indicate that my pupils were initially dilated in the darkness and then constricted when I began looking at my bright phone? I wonder how significant the difference is…

It's funny that I'm reading this thread because I just went through this exact same thing last night and it was weird. I don't ever make a habit of using my phone in the dark, but I did yesterday and I did at full brightness and for many hours and it did not feel good.

Eventually after like 6 hours in the dark and accidentally using just one eye for reading- eventually I started to see really trippy and weird visual noise in the dark areas of the room. I also noticed that if shone at the right angle- the pitch black areas of the room suddenly lit up, as though I was giving my over-exposed eye some kind of night vision, which is weird because you'd expect an oversaturated eye to be completely blind in the darkness.

Now this is all anecdotal, but reading screens in pitch black light has always felt bad for me. I don't understand people who insist on watching TV shows or movies in a fully pitch black room. I mean I get why school teachers and home theater enthusiasts do it- but for normal TV viewing, it just seems wrong to me.

Re: Chemists discover how blue light speeds blindness

#172

Post by herf »

mafuyu wrote: post #44

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 i…

Yes, also if your eyes are closed when it starts, 500nm is better because more gets through the eyelid. Better if you diffuse more and spread out the light over more of the visual field.

But the main thing you'll want to make sure is that you can get enough light. There is some evidence that >200 lux with this wavelength will help, but most light therapy uses tons of light (1500 melanopic lux or more):

https://fluxometer.com/rainbow/#!id=Light%20Therapy/ReTimer

Re: Chemists discover how blue light speeds blindness

#173

Post by tough_luck »

wpasc wrote: post #156
herf wrote: post #136

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…

Thank you for your input, but I mostly want to thank you for f.lux. It has been one of my favorite things for a long time. It's silly how long it's taken companies to provide a native blue light filter and your product just kicks ass. If you guys ever wanted to figure out your app on a smart TV (or apple TV), I know there'd be a lot of thankful people! Also, I'd love to contribute to the ongoing dev of f.lux (I don't…

For my Samsung TV I use movie mode and also change colour temperature to warm.

Re: Chemists discover how blue light speeds blindness

#174

Post by lphnull »

asdkhadsj wrote: post #49
rgrove wrote: post #41

Earlier quoted context omitted.

Hmm. If I've been in the dark for a while and then pick up my phone, the brightness hurts my eyes for a moment until they adjust to it. When I put the phone down, it takes a moment before I begin to be able to see things in the dark room. Doesn't that indicate that my pupils were initially dilated in the darkness and then constricted when I began looking at my bright phone? I wonder how significant the difference is…

If it is the delay in dilation that causes the damage, I imagine it's exacerbated by constantly changing dilation as well. Ie, if I'm staring at my phone in the dark, I rarely keep focus on it. I often glance to the left or w/e, thus causing the screen to appear too bright again. Same for laptop-ing in the dark. I often find myself looking at keys, or thinking off in the distance, or w/e.

serious question: Why do people like to do work or leisure in pitch black rooms? Don't you feel clumsy, sleepy and uncomfortable when everything is dark? How can anybody go more than 10 minutes without needing to use vision to interact with their surrounding environment?

I personally can't have the lights off even if I'm watching a movie. Maybe because I was raised without TV, I can't sit still for more than 20 minutes watching entertainment before I feel the urge to do something productive like wasting time on the internet.

Re: Chemists discover how blue light speeds blindness

#175

Post by applecrazy »

shanev wrote: post #126
Eric_WVGG wrote: post #119

Earlier quoted context omitted.

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 bingin…

First point is incorrect. Night Shift's color temperature is adjustable, which includes the blue level.

While the color temperature is adjustable, I've found (anecdotally) that the warmest setting on Night shift is still quite a bit more blue compared to the max warmness on F.lux.

(Tested on iMac and MacBook Air, may be different for other screens)

Re: Chemists discover how blue light speeds blindness

#176

Post by solarkraft »

erikbye wrote: post #166
arama471 wrote: post #161

Earlier quoted context omitted.

I assume you mean the night light button in the action center? If so I would argue f.lux does a lot more. For one thing you can choose the hue it goes to, but also unlike the Windows 10 one which (AFAIK) is simply on/off, f.lux will adjust based on a schedule which means that you don't typically notice the effects (as the change happens slowly). This, combined with the ability to change damn near every parameter it u…

Both macOS and Windows 10 has on/off now, scheduling, less/more warm adjustment. Windows 10 even has sunset to sunrise based on location. EDIT: HN is becoming more like Reddit every day, I see. Ridiculous. Down-voted for pointing out the existence of helpful features. EDIT: might have been my fault.

I know these features exist in some places. But nobody had it before f.lux. And it's still - imo - one of the best implementations.

Re: Chemists discover how blue light speeds blindness

#177

Post by dsr_ »

_nkoa wrote: post #32
rgrove wrote: post #19

> 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?

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 m…

... but I don't put a 100% brightness screen in front of my eyes at night. Do people really do that? Don't they know how to adjust brightness?

Indoors, I use about 30% brightness. As the day gets dimmer, that slides down to about 25%. If I'm reading something in bed, I start at about 10% and as my eyes adapt, go down to 1%. When I'm finding it hard to keep my eyes open, I take that as my signal to go to sleep. Am I ridiculously unusual?

Re: Chemists discover how blue light speeds blindness

#178

Post by visualstudio »

erikbye wrote: post #152
taneq wrote: post #150

Earlier quoted context omitted.

Hijacking this for a moment to say thanks for f.lux :) I've been running it for years and it's one of those things where you don't really notice the effect until you turn it off and then EGADS MY EYES.

Windows 10 has this built-in, so does macOS.

I've been a flux user for years, but sadly I had to switch to the Windows 10's version. Flux causes a 1 frame lag every 60 frames which was driving me crazy. Only fix was to put it into Safe Mode, but Flux is really janky in that mode; especially when alt tabbing. The Windows 10 version also has no lag while shift colors. It's a shame. I'd love to have kept supporting flux.

Re: Chemists discover how blue light speeds blindness

#179

Post by hestipod »

onnnon wrote: post #130

I wear computer glasses at all times when working, and highly recommend them. It greatly reduces eye strain, and filters blue light. If anyone is looking for a good pair, I buy mine from Gunnar [0] (no affiliation). [0] https://gunnar.com/

Tried these and some Uvex glasses that block 100% of blue light (Gunnars are very low % blocking relatively). Zero impact on my strain. I have seen many others state the same. It's obv there are many causes for strain, just wish I could figure mine out.
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