maybe it should be "the orange"

September 6, 2018 8:49 AM

Blue light excited retinal intercepts cellular signaling is the paper by Kasun Ratnayake, John L. Payton, O. Harshana Lakmal & Ajith Karunarathne that launced a thousand headlines: Is Blue Light From Your Smart Phone Harmful To Your Eyes? Chemists discover how blue light speeds blindness

Dr. Karunarathne is emphatic on his website: CLARIFICATION: OUR FINDINGS DO NOT SHOW THAT LIGHT FROM DIGITAL DEVISES CAUSES BLINDNESS!

Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness., Chang AM, Aeschbach D, Duffy JF, Czeisler CA. Proc Natl Acad Sci U S A. 2015 Jan 27;112(4):1232-7

Light-emitting diodes (LED) for domestic lighting: any risks for the eye?, Behar-Cohen et al. Prog Retin Eye Res. 2011 Jul;30(4):239-57

Effects of blue light on the circadian system and eye physiology, Gianluca Tosini, Ian Ferguson, and Kazuo Tsubota, Mol Vis. 2016; 22: 61–72.

The use of blue light is becoming increasingly prominent in our society, and a large segment of the world population is now subjected to daily exposure (from a few minutes to several hours) of artificial light at an unusual time of the day (night). Because light has a cumulative effect and many different characteristics (e.g., wavelength, intensity, duration of the exposure, time of day), it is important to consider the spectral output of the light source to minimize the danger that may be associated with blue light exposure. Thus, LEDs with an emission peak of around 470–480 nm should be preferred to LEDs that have an emission peak below 450 nm. Although we are convinced that exposure to blue light from LEDs in the range 470–480 nm for a short to medium period (days to a few weeks) should not significantly increase the risk of development of ocular pathologies, this conclusion cannot be generalized to a long-term exposure (months to years). Finally, we believe that additional studies on the safety of long-term exposure to low levels of blue light are needed to determine the effects of blue light on the eye.

Removal of the blue component of light significantly decreases retinal damage after high intensity exposure, Javier Vicente-Tejedor et al. https://doi.org/10.1371/journal.pone.0194218

Why tech’s favorite color is making us all miserable

posted by the man of twists and turns (23 comments total)

So the mods should change the background color on Metafilter?
posted by njohnson23 at 9:05 AM on September 6, 2018 [7 favorites]

Relevant: for a couple of years I'd noticed that pure blue signage looked weird to me and kind of freaked my eyes out. Then one day, looking at a coffee maker, I realized that the blue power light was noticeably dimmer in one eye than the other. The same thing did not happen for any other color of LED light. I also noticed that it was only dim in the center of my vision, and also that, if I blinked repeatedly, I could see a shape in the center of my right eye that looked like a pupil.

So I went to the ophthalmologist and she did a full scan and it turns out I have a macular pucker, which is a small span of cells that covers the little hole in the back of your eye. That explains the shape I'm seeing, and also makes sense since it is a precursor to vitreous detachment (which runs in my family), but she was flummoxed about the blue thing.

I wouldn't be surprised if this were connected to cell phone / laptop use at night.
posted by grumpybear69 at 9:23 AM on September 6, 2018 [4 favorites]

I was alarmed to see a paper about eReaders in this post -- however, I took a look at it, and it seems the "eReader" used in the study was specifically an iPad (which, while electronic and capable of reading books, I wouldn't usually consider as an eReader).

So I can continue to feel good about swapping over from my phone to my Paperwhite before bedtime, until faced with evidence to the contrary, right? (Nevermind the other 15 hours of my day)
posted by Gordafarin at 9:27 AM on September 6, 2018 [3 favorites]

This is relevant to my interests, but I’m reading this on my phone in the lunchroom, so...
posted by saucysault at 9:27 AM on September 6, 2018

So the mods should change the background color on Metafilter?
A professional orange background should do the trick.
posted by davros42 at 9:33 AM on September 6, 2018 [5 favorites]

Another reason not to shop at K-mart
posted by condour75 at 9:36 AM on September 6, 2018 [4 favorites]

So, to be clear on this one, Removal of the blue component of light significantly decreases retinal damage after high intensity exposure, it's important to note the bit about the mice:

Three experimental groups were designed. The first group was unexposed to light, the second one was exposed and the third one was exposed and protected by a blue-blocking filter. Light damage was induced in young albino mice (p30) by exposing them to white light of high intensity (5,000 lux) continuously for 7 days. Short wavelength light filters were used for light protection. The blue component was removed (94%) from the light source by our filter. Electroretinographical recordings were performed before and after light damage. Changes in retinal structure were studied using immunohistochemistry, and TUNEL labeling. Also, cells in the outer nuclear layer were counted and compared among the three different groups. Functional visual responses were significantly more conserved in protected animals (with the blue-blocking filter) than in unprotected animals. Also, retinal structure was better kept and photoreceptor survival was greater in protected animals, these differences were significant in central areas of the retina. Still, functional and morphological responses were significantly lower in protected than in unexposed groups. In conclusion, this blue-blocking filter decreases significantly photoreceptor damage after exposure to high intensity light. Actually, our eyes are exposed for a very long time to high levels of blue light (screens, artificial light LED, neons…). The potential damage caused by blue light can be palliated.

So, a couple of things:

a.) This experiment was on mice, not humans.

b.) The mice were albino. This means, among other things, that the mice in question lacked pigmentation in their retinal epithelial cells, meaning their retinas were significantly different than non-albino mice, let alone non-albino humans.

So, like Karunarathne's research, there are a whole bunch of things going on here that means all of the clickbait stories that have appeared about it are largely noise and bullshit.

So:

1.) Does it bear further investigation? Absolutely, especially considering the ubiquity of screens and other LED applications in our lives.

2.) Is YOUR PHONE BLINDING YOU BUY THESE GLASSES AND SCREEN COVERS AND TAKE THESE SUPPLEMENTS TO PROTECT YOUR EYES? Nope.

I'm no scientist, but I'm married to someone with a congenital retinal disease and I've spent a ouple of decades reading ungodly amounts of the research literature on the topic and have parsed years of alarmist/miracle cure "journalism" about the eye during that time. Layperson's takeway? The lens part of the eye is relatively easy. The retina's pretty darn complicated, and the sort of "journalism" that prompted Karunarathne to issue the emphatic clarification about his work doesn't help people's overall understanding of its physiology and risks to it.

Also, one bit of bad news - your eyes are going downhill from pretty much day one, the question is "How much in your individual case?"

And all of which to say is that bona fide experts in the field can feel free to tell me if I'm talking out my ass.

As a side note, I've always experienced dark blue LED christmas lights as "blurry," meaning as a very nearsighted person they say to me, "Time to get your prescription checked," while the other lights in other colours adjacent to them appear not-blurry.

Fuckin' eyes. How do they work?
posted by mandolin conspiracy at 9:37 AM on September 6, 2018 [15 favorites]

2.) Is YOUR PHONE BLINDING YOU BUY THESE GLASSES AND SCREEN COVERS AND TAKE THESE SUPPLEMENTS TO PROTECT YOUR EYES? Nope. We don't know.

From Karunarathne's website:

Whether blue light from mobile devises and digital screens induces similar toxicity levels is an unanswered question and is currently under investigation. Even if such a scenario is found, since the studies are done in cultured cells, that would not indicate that these devises can cause similar damages to the vision. Nevertheless, some literature reports suggest that removal of blue component from intense light can reduce vision damages

The ubiquity of LED screens is a relatively new phenomenon (~10-15 years) and whether or not they are having a deleterious impact on our vision is far from an answered question. Certainly we shouldn't panic and give into the fear-mongering of bad pop science journalism, but neither should we say "nothing to see here, move along."
posted by grumpybear69 at 9:50 AM on September 6, 2018 [1 favorite]

Don't you see! This is just what the Triffids want!
posted by TheWhiteSkull at 9:53 AM on September 6, 2018 [3 favorites]

I've always experienced dark blue LED christmas lights as "blurry,"

Same here. Blue spotlights on performers are blurrier than other colors, too, and have been long before I began reading from screens a lot.
posted by Johnny Wallflower at 10:24 AM on September 6, 2018 [5 favorites]

I was alarmed to see a paper about eReaders in this post -- however, I took a look at it, and it seems the "eReader" used in the study was specifically an iPad (which, while electronic and capable of reading books, I wouldn't usually consider as an eReader).

I would like to see a study on actual ereaders, not tablets or phones. My eyes feel less tired when I use my Kindle, but I don't know if that's a real thing or not.
posted by betweenthebars at 10:30 AM on September 6, 2018 [2 favorites]

As a side note, I've always experienced dark blue LED christmas lights as "blurry," meaning as a very nearsighted person they say to me, "Time to get your prescription checked," while the other lights in other colours adjacent to them appear not-blurry.

Has to do with Chromatic Aberration. more info here
posted by ArgentCorvid at 11:03 AM on September 6, 2018 [4 favorites]

So I can continue to feel good about swapping over from my phone to my Paperwhite before bedtime, until faced with evidence to the contrary, right?

No. White light contains blue light, which won't damage your vision but will mess up your circadian rhythm and keep you awake.

This is true no matter the source of light - there's nothing fancy about modern screens that makes them worse than CRTs or even bright lightbulbs, save for the way we use them. Using a phone or tablet in bed is a good way to make yourself feel tired all the damn time.

But the good news is that there's a very simple and cheap fix that doesn't require changing your pre-bedtime reading/phone-using habits. Simply buy a sheet or two of Rubylith off eBay or a local art supply store, cut it to size to cover your screen, slip it inside your phone case at night and you're good - the Rubylith is an extremely effective filter that only lets through red light, which does not affect your circadian rhythm or disrupt night vision. Costs maybe five bucks for enough to cover the average laptop screen, and touches still register through it.

If you're a fan of paper books or non-backlit ereaders, you can cut enough Rubylith to cover the LEDs in any reading lamp, and hold this filter in place with electrical tape.

Some people install apps that turn their screens pink or light orange at night - these don't really work all that well, as these apps work not by reducing the amount of blue in the picture but by increasing the amount of red. If you have a rooted Android phone you may be able to turn off the blue on your phone via an app or system settings in a custom ROM - if you're unsure of whether you've eliminated blue light, just look for pink. If you can see pink, you're just adding red on top of the blue and green, which won't have much (if any) beneficial effect.
posted by FeatherWatt at 12:14 PM on September 6, 2018 [6 favorites]

I'm not familiar with the state of LED backlighting but I've had a product with blue discrete LEDs fail EU certification because our purchasing dept found cheap asian parts that gave off all kinds of bad near-UV spectrum. I would hazard to guess that a large majority of blue parts out there in the USA are not in the safe zone and nobody is bothering to check any of it.

Here's Cree's guide to blue LEDs. It's pretty serious stuff.
posted by JoeZydeco at 12:59 PM on September 6, 2018 [2 favorites]

For what it's worth, when I'm in bed at night I use iOS' color filter capability to cut out everything except red, and MeFi is perfectly legible. It feels like it's improved my ability to fall asleep too; no news on whether it's letting through enough blue/uv to fuck up my eyes in the long run.
posted by egypturnash at 2:17 PM on September 6, 2018 [5 favorites]

I'm no vision scientist, but this looks like the equivalent of feeding mice hyper-megadoses of artificial sweetener and noting that they get sick.

5000 lux is a lot. Typical lux in a home is 150; in an office, 500. On the other hand, go outside into direct sunlight and you may get 50,000 lux.

Another detail from the study: the rats' pupils were artificially dilated.

The scientists seem to be using "blue" as a shorthand for "high-frequency". Don't take it too literally: a violet or ultraviolet lamp is producing more energy than a blue one. (And the blue background of MeFi is not producing more blue light than a white background.)

So far as I know, the only thing distinctive about a computer screen is that it's a bright light that we sit close to.
posted by zompist at 2:20 PM on September 6, 2018 [3 favorites]

You might not be a vision scientist, zompist, but you've got it dead right.

I am a vision scientist, and I've done experiments where we've needed 5000 lux ambient illumination in the lab. That's surprisingly hard to do, even with modern LEDs. You're talking several of the big LED light panels that get used for lighting video shoots (not the small on-camera ones either - think about 8" x 12" and packed solid with LEDs). To get 5000 lux at a distance of about 5' (because our subject needed somewhere to sit), we needed two of these, pretty much dialed up to max.

If your LED monitor or your phone is punching out 5k lux, you'll notice (and you won't be able to use it). So, yeah, I wouldn't worry about this too much. The whole concern about screen time is probably "we're staring at light sources in ways our visual systems aren't really assuming we're going to" rather than "the perceptually blue end of the visible spectrum is going to melt our retinas."
posted by Making You Bored For Science at 4:14 PM on September 6, 2018 [12 favorites]

Thanks for the iOS tip, egypturnash. I'll give it a try.
posted by Johnny Wallflower at 4:31 PM on September 6, 2018

I got a pair of those blue-blocking glasses, and I find it really does make a difference in how tired my eyes get after an 8-hour metafilter shift. It really seems to help with eyestrain. Can't say if it makes any other difference!
posted by Eyebrows McGee at 5:11 PM on September 6, 2018 [1 favorite]

The return of blue-blocking sun glasses, this time in the workplace.
Blue light is ubiquitous. Someone's gonna get rich because this fear's got legs!
posted by Fupped Duck at 6:15 PM on September 6, 2018 [1 favorite]

these apps work not by reducing the amount of blue in the picture but by increasing the amount of red

This is not true of f.lux or of the built in Night Shift on MacOS or iOS. I'm unaware of any apps that this is true of.
posted by dmd at 5:45 AM on September 7, 2018

> To get 5000 lux at a distance of about 5' (because our subject needed somewhere to sit), we needed two of these, pretty much dialed up to max.

Thanks for this eponysterical fact, Making You Bored for Science, but what does this mean for those of us with seasonal affected disorder, who sit less than a meter from a 10,000 lux lamp for more than half an hour, daily?
posted by Jesse the K at 1:13 PM on September 7, 2018 [1 favorite]

I'd say there's nothing to worry about - 10,000 lux is bright (it's meant to be, to be effective), but it's not going to do you any harm. I'd be surprised if it was pleasant to stare directly at the light box, but they've usually got diffusers. For that matter, 10,000 lux is pretty much the bare minimum if you want to simulate daylight - a really bright day can get up past 20,000 lux.
posted by Making You Bored For Science at 6:28 PM on September 14, 2018 [1 favorite]