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The Effects of Computer Use on Eye Health and Vision (1997) [pdf] (aoa.org)
123 points by walterbell on Jan 14, 2018 | hide | past | web | favorite | 99 comments



While we’re here, lets do a quick eye-related work checklist:

1. Monitor should be arms length away. 2. Brightness should conform to the light in the room. 3. Try to get a good bit of ambient light from the side (via a lamp or window). 4. Keep eyes at a 10-15° downward angle on the monitor. 5. Take a break every hour and let your eyes rest for a second. 6. If you have glasses, wear them.

Those six principles will go a long way toward keeping your eyes happy!


These are great. Another thing my eye doctor suggested is to practice the 20-20-20 habit. Every 20 minutes, shift your gaze to something 20 ft away for 20 seconds. I'm usually able to feel my eyes releasing tension after about 15 seconds.


I also use glasses that block blue light. The difference for the eyes is amazing. I should have started sooner wearing them.

When nobody is around I swap the glasses for a pair of geeky plastic amber lab protection, which block more blue light than any other solution. Sure, the OS or flux, for example, can block some, but a physical solution is reliable.


Glarminy has a detailed review of blue light filters, https://glarminy.com/2016/05/06/blue-filter-light-sensitivit...


I've got a blue-blocking coating on my current pair of glasses. I can't say that I really see the benefit, but I do notice all the colors being yellow-shifted and blue/purple glare any time there's a source of light to my side or behind me.


I've tried a number of glasses without prescription to test the blue blocking. They are available from the websites (Zenni, EyeBuyDirect, Gunnar, jandsvsion, etc) or from amazon and excepting Gunnar can have the cost no more than $10.

The glasses are "hit and miss" with the blue blocking. I don't know if the process is partially manual, but the amount of blue light that gets blocked is not always the same between two pair from the same manufacturer. Different manufacturers use different technologies to block the blue, some of which block almost nothing.

Once I got a pair that blocked enough blue light, though, I really noticed a difference in eye-strain and length of time I could look at the monitor. The cheapest and best, strangely, is the plastic amber lab eye covering. Those block far more than any other pair of glasses and work the best for me.


Indeed, the friendliest way to position/orient a display is as far away as you can comfortably put it to see all the small details you need to see (the further it is, the less the muscles in your eyes have to work to converge/focus), with the top of the display at or slightly below eye level (eyes are designed for looking downward for close work, and both converge and focus closer comfortably when looking at the lower part of the field of view), and the display tilted back a bit (15°?) at the top. Many “ergonomics guides” (and anecdotally from walking around various tech company offices, the vast majority of programmer workstations, in practice) get this one very wrong, recommending a display with eye level somewhere around the middle of the display, and the display oriented perpendicular to the table. Try to glance around the room at further objects relatively frequently, and occasionally stand up to walk around and take a break from close work.

Make sure to also sit up straight, not hunched or slouched, with the keyboard near the torso (the close side maybe half a foot from the belly), and upper arms hanging loosely at the sides. The palms/forearms should be free floating, not resting on any surface. At all costs keep the wrists as straight as possible. Typing should be light and springy.

Adjust the tilt of the keyboard so that its surface is approximately parallel with the forearms. A split keyboard which is tented even a little bit upward toward the middle and turned a bit so that the far side points inward relieves quite a bit of strain by reducing wrist pronation, but is not strictly necessary.

Unfortunately there hasn’t really been very much large-scale, carefully scoped and controlled, properly conducted/analyzed, anatomically motivated study of keyboard ergonomics. That is, there have been a large number of research studies but almost all of them were garbage for one reason or another. As a result many of the most important conclusions about proper typing style can best be discovered by reading directly about anatomy, investigating proper technique for other tools, and doing careful personal experimentation/analysis. Reading keyboard-specific ergonomics literature does not necessarily lead to healthy recommendations or physical keyboard designs.


> get this one very wrong, recommending a display with eye level somewhere around the middle of the display

Maybe this is because I wear glasses and don't move my eyes much (tend to move whole head when shifting gaze because looking through center of glasses works best), but when my monitor is low, it eventually causes strain on my neck and shoulders. It also causes me to slouch a lot as I try to fix the positioning subconsciously.

Before I had a monitor with a riseable base, I used to put my monitor on a book or two.


In general people can keep their heads upright and balanced above the spine. It is not in general necessary to move or turn the head to look slightly downward. No idea about glasses though.


Your recommendation doesn't take into account monitor size. If you always keep the top at eye level, the larger a monitor you get (assuming same distance away), the farther and farther down most of the monitor will be. Monitor sizes have grown a lot over time.


I have a 27 inch display, and the top of it is easily 6 inches below my eye level. It is about 3 feet away from me, so about 5°–35° angle measure below my eye level from top to bottom. It’s perfectly comfortable to see the whole display without moving my head from an upright position.

Put the display on an VESA mount attached to an articulating arm and put the bottom of the display bezel directly on the table or slightly above. Maybe if you have a 40 inch display it starts getting tough.


Was curious and decided to test it out. Swiveling my eyes horizontally works great, no head movement needed unless I'm looking at the far edges of the screen.

Up-down, I move my head almost immediately.

My understanding is that glasses have an optimal viewing angle centered around your pupils where your perscription is perfect. As you start looking through different parts of the lens, it gets less perfect. At extreme angles you start seeing the frames themselves and it's annoying.


Freeform and digitally surfaced single-vision lenses have less peripheral distortion away from the optical center of the lens. Round/oval metal frames will reduce visibility of the frame edge, if the frame fits well and the eye size is tall enough.

Lenses: Essilor “Eyezen+ 0” CR-39 lens+AR is ~$120 online or Zeiss Individual SV ~$300. If you have prescription with sphere stronger than -3, the improvement in peripheral vision can be useful for large or multiple monitors.


> 6. If you have glasses, wear them.

Is that for people who need glasses but don't wear them, or wear corrective lenses (of some sort) all the time but really should use glasses because there somehow better?

Seriously, I want to know, being the latter part.


I think it’s the former. Not wearing corrective lenses (glasses or contacts) when needed causes additional eye strain.


Both. Glasses are much healthier for your eyes than contacts. Computer usage = less blinking = less moisture = more harmful with contacts.


Does bullets 2 and 3 apply if a monitor fills major part of FOV?


Yes, ambient light affects pupil dilation.

You want to avoid focus-locking the eyes to a single distance. It’s better to have the monitor further away so there are other objects in your field of vision, preferably more distant than the monitor.


This document was published in 1997. I know it's anecdotal, but I've always felt that staring at a cathode ray tube was decidedly more fatiguing than staring at a flat panel. Is it just me or is there some sense to this?


As far as I know there are 4 causes of eye fatigue from CRTs: 1) constantly looking at the same distance. This is the same with LCD and xLED displays, or even paper books; 2) refresh rate 3) intensity of the light emitted (on its own and compared to surrounding environment) 4) particles fired at your face by the magnetic field generated by the CRT

As far as I know, cause 4) has the most impact, dust particles were literally fired at your eyes, and for this reason 20 years ago it was relatively easy to see people with grounded filters mounted to their CRTs (you used to attach the ground wire to the ground contact of the RS232 or parallel port of the PC)


> 4) particles fired at your face by the magnetic field generated by the CRT

> As far as I know, cause 4) has the most impact, dust particles were literally fired at your eyes, and for this reason 20 years ago it was relatively easy to see people with grounded filters mounted to their CRTs (you used to attach the ground wire to the ground contact of the RS232 or parallel port of the PC)

I've always wondered whether this actually worked, since I had the impression that the grounding was BS and all those filters did was reduce glare.


It is also anecdotal, but I feel exactly the same. CRTs are far more fatiguing flat monitors for me.


It could be because of the refresh late. Officially, people can't tell the difference past 60hz, but I've always found anything less than 75hz gives me migraines.

[[At least, the only times I've had a migraine in the last three or four years were when I was setting up a new system and forgot to frob the monitor to 75hz (I don't understand why it doesn't just automatically detect this stuff. But there we go...)]]


If you're trying to confirm that flat panels are better (anecdotally) than CRTs, I'm not 100% sure I follow your logic here, because:

- Most CRTs, generally, could operate at 75Hz on the low end and upwards towards/beyond 120Hz on the high end if set in the system settings

- Most flat panels default, and may be capped, to 60Hz (unfortunately including the one I'm on now) and only in recent history do they have relatively expensive options boasting 120Hz


Flat panels differ in one very important aspect though. A CRT monitor achieves its refresh rate by briefly illuminating phosphors on the surface of the monitor, and relying on human persistence of vision to achieve an image. The CRT monitor is only actually illuminating a single pixel at a time, and simply scans the surface very rapidly. So, increasing the refresh rate on a CRT monitor has a very visible impact on the smoothness of the image and the visibility of any flicker.

Flat panel monitors may only have a 60 Hz refresh rate on average, but each lit pixel is illuminated 100% of the time. The refresh rate dictates how long each pixel takes to change to a different color and affects the smoothness of motion and video, but a static image on a flat panel display should have no flicker at all.

(Assume for a moment that the flat panel's backlight has no inherent flicker; some flourescent backlighting suffers from this, but it's unrelated to the display's refresh rate. I'm also glossing over some of the finer technical details in both kinds of tech.)


> relying on human persistence of vision

FYI: persistence of vision was debunked back in 1912[1], 1976[2], and again in 1993[3]. It's still taught in film classes, and they justify this by claiming that it's "disputed". It's not disputed, it's downright incorrect. Please stop referring to it, as this only confounds the idea, and helps it with false validity.

[1]: https://www.researchgate.net/publication/34413805_Experiment...

[2]: https://www.researchgate.net/publication/268400050_The_Myth_...

[3]: https://www.jstor.org/stable/20687993?seq=1#page_scan_tab_co...


From an eye strain point of view, the big distinction between an LCD and a CRT at the same refresh rate is that the LCD’s backlight is on continuously; a CRT flickers at its refresh rate. 60 Hz flicker is easily visible, and, at least for me, isn’t particularly comfortable to look at (I used to crank the refresh rate up on my monitors for this reason).

LCD monitors with PWM-dimmed backlights can have the same problem, but they usually run at higher frequency. I still run non-PWM monitors for my daily work, though.


Flat panels do not flicker [1]. Regardless of the refresh rate their pixels stay constantly illuminated.

[1] At least not in the sense of CRTs. Most do perform temporal dithering of colors by alternating between nearby shades.


And GTX9xx/10xx GPU's, most AMD GPU's and Macbook Pro external display outputs use temporal dithering, regardless if the display is native 8-bit or not.

I'm working on a .kext to fix the latter, but it's hard work and we still have a long ways to go.


Recent HN thread on display flickering: https://news.ycombinator.com/item?id=16087871


We were told that you had to frequently move away from a cathode ray tube, to let the radiation dissipate. Of course, this didn't happen often enough.

The annoying thing about CRTs was the amount of space they took up.

My eyes feel increasingly worse, even though resolution and perceived clarity seems to be better. I put that down to age.

I didn't really like the brightness of my first flat panel monitors, and expected improvements with my led back-lit laptop (thinkpad), but I've never really enjoyed looking at that either.

So to me it's all a bit uncomfortable. E-ink on the other hand, I love.


In 1997 the majority of monitors were CRTs, so lines were naturally fuzzy and I think this is a large part of what causes eyestrain --- the inability to focus clearly. I remember upgrading to an LCD and the sharpness was amazing. I think widespread subpixel antialiasing later made things worse; when I first tried it, the text looked "too smooth" and I got dizzy, watery eyes because it felt like I constantly couldn't focus. Now I make it a habit of always turning it off, and I suspect the studies that say it increases reading speed are because for most people it subtly makes them want to not stop and focus --- it's subconsciously unpleasant to.


Are there differences in subpixel antialiasing between Windows, Mac, Linux, iOS, Android?


See this article on font rasterization [1] for a primer. The software used makes a big difference.

[1] http://www.antigrain.com/research/font_rasterization/index.h...


I would think so. I imagine it depends on the specific rendering system. XCB/Xorg is going to antialias text differently to Areo due to using different libraries. I think within linux at least it also depends on the application. I seem to remember that Qt and GTK have different font rendering systems.


you can also tune subpixel aliasing to your liking in windows, using the 'adjust cleartype text' - has been there in a while and even used to support different screen striping https://www.gnostice.com/nl_article.asp?id=189&t=Is_ClearTyp...


I remember when i first started using the computer late into the night, around 3 am. that sure caused some problems, including floaters and astigmatism.

one factor people miss is that, it's not just the amount you spend staring at screen that causes eyestrain and headache, but also how focused you are, we squint a lot when we focus and that appearantly is an issue, looking at a screen for 3 hours without having to think hard versus 1 hour of hard squint, the 1 hour is more damaging. for me at least...


I think the floaters are a function of both getting old, and brighter "white" displays.

I started noticing them about 10 years ago when I got my first iMac. Prior to that I'd mostly used smaller CRT displays, suddenly my field of view was taken up by this big white screen and what were those dark shadows floating around my view...

A few years on and I still see them, especially when using a 21+ inch screen on white web pages. Just part of get old...


From what I understand accumulation of 'floaters' is common for most (all?) people as they age, though some people surely have more problem with them than others. I have never heard that looking at computer displays causes any particular effect on the rate at which they develop.


i have a 13inch macbook pro and a desktop with 25 inch screen, i rarely ever see floaters on the laptop but i do on the desctop. so a maximized browser is a big no no.

making the text larger helps as well.


did those floater eventually resolve, are you myopic? I'm one, see tons of those darn f*ckrs, do dev work so stuck in front of a screen... was wondering if your case is different


I had perfect vision before i got the floaters and people faces started to look more and more blurry as time went by, was learning programming these days. the eyestrain and headache caused me some depression. it was only after i got the glasses i didn't feel so much eyestrain anymore and stopped to notice the floaters. my glasses have anti-reflex they filter the blue wave, so it made things easier.

except when i look at bright light, or if i am tired. they will always be there. forever... unless you do an operation, which you should not do unless they are causing real issue for your sight.

i have had them for 6 years now, panicked the first year or two i had them because they were so many and you can't just look away...

but i get my eyes checked every 6-12 month, and see if i need correction for my astigmatism.


Sounds the same as me, I’m myopic and first noticed them ~8 years ago. In one eye I have a fairly big dark one (around the size of a tennis ball at 4m distance).

At first I couldn’t stop noticing them, but after a year or so I got used to it, and it hasn’t gotten worse. My myopia has improved though...


I got those couple of months ago too. I got my eyes tested thoroughly but they didn't find anything. Only explanation I got was ageing.

I did a screen free 2 weeks but it didn't do anything.


Have any of you people who work as software developers (or similar professionals who spend most of their days looking at a screen) gotten Lasik eye surgery? Have you noticed any regression in vision after the treatment as a result of your screen usage?


disclaimer: not medical advice, please consult opthalmologist

If you are nearsighted and wear your full distance prescription for extended near (computer/reading) work, there is some chance that your eye will adapt to the most dominant distance, eventually requiring a stronger prescription for distance/driving. Rinse/repeat = ever worsening glasses for some people.

To avoid this problem, ask your optometerist for a separate (weaker) prescription for computer glasses. You can get a ballpark idea from http://computerglassesrx.com. Glasses are cheap these days, e.g. online from Zenni for less than $50.

Lasik carves a lens onto your eyes. If that lens strength is your distance prescription, the same issue exists as with glasses. To reduce close-up strain on your eyes, you can use plus lenses for close-up work, which reduces the lasik/contacts "minus" prescription for near distances. Look at the calculator above for an estimate, but consult an eye doctor, as there are variables like age/presbyopia/convergence.

Previous HN thread on Lasik: https://news.ycombinator.com/item?id=9941566

Non-mainstream discussion of plus lens therapy: http://forum.gettingstronger.org/index.php?topic=1115.0


I can second the advice about the 2nd set of glasses.

Last time I upgraded my prescription I asked my optometrist about working in from of a computer all day, and he said "If you can see the screen without wearing any glasses, do that. Otherwise use your old ones (with the less powerful lenses)."

Since I've been doing that, my eyes have felt a bit better. Maybe I could get away with an even weaker set, but I haven't really looked into it.


Since getting some computer glasses my eyes have gone from deteriorating every year to getting slightly better. Might be a coincidence but I suspect not. Next time I'm in Asia I'm going to get an even weaker pair and see if my eyes can keep improving.


Cliff Hayes successfully went down that unsanctioned road, he published some videos [1] and a PDF [2]. We need more scientific studies [3] to figure out why undercorrection works for some people.

When it works, the key seems to be relaxing the eyes and surrounding muscles while viewing objects at a distance which causes just enough blur. Within a minute or two, the brain's visual cortex figures out a "software compensation" for the signal coming from the eye, which lets the eye stay relaxed instead of straining to focus. More info on Vision Therapy is available from behavioral opthalmologists, but it takes time, motivation and may not be covered by insurance.

[1] https://youtube.com/user/cliffgnu

[2] https://drive.google.com/file/d/0B5REdzibAJQ4VFJuWnZCU3dLcHc...

[3] https://dspace.mit.edu/openaccess-disseminate/1721.1/105363


This is purely anecdotal. I have a bad astigmatism. I tend to not wear glasses until I have to. In the garden I don't bother. And oddly, when I do use my glasses everything becomes too much. In my mind scenery becomes unpleasantly cluttered/dirty. It's quite horrible. I prefer the soft focus - but can't read the laptop, watch TV without.


If your astigmatism (cylinder) and/or spherical diopter numbers are very high, your glasses may have significant distortion when looking through any point other than the optical center of the lens, e.g. for peripheral vision. Have you compared contacts with glasses? They provide a much wider field of view.

If you like soft focus, you can try on different drugstore reading glasses (e.g. +0.50) over your normal glasses, to find a reduced strength which lets you see at the desired distance without super-duper-sharp edges. Then ask your optometrist to provide you with a reduced prescription for non-driving or near work tasks. Otherwise, they will prescribe driving-strength glasses to avoid legal liability.


Interesting, my prescription was out of range for contact lenses when last explored. It might be worth me getting something as best as they can get if the contact effect is beneficial.


If your prescription is out of range for contacts, it means it is very weak, so there shouldn't be much distortion in glasses, hence you won't see much difference with contacts.

Easiest would be to find a friendly optometrist who will put your astigmatism prescription into a trial frame, then let you self-adjust the cylinder and axis values until you find your desired blend of clarity and softness at your target distance. They can also advise on the safety of using that prescription vs using no glasses.


I had Lasik in 2003 and was wearing glasses again by 2008. My mom had it done at the same time and took about the same amount of time to get back to glasses. She's in front of a computer a good chunk of time but not nearly as much as I am. Not sure what that says about lasik or screen use, it's just what happened.


I've heard of different "kinds" of Lasik. Do you know which "kind" you had done? (That's a loaded question as I'm not even sure I'm asking the question correctly).

Also, what did it correct? Did you wear glasses 24/7 before?

Genuinely intrigued. Being as I'm 100% dependent on my glasses/contacts I'd really like a solution, but feel like it'll be the same sort of outcome.


If you gives you any hint about which "kind" I had, my procedure involved cutting and folding back of the lens. I've heard they don't always need to do that now. I'm nearsighted. I always wore glasses before and now I'm back to always wearing them. Again, I'm not sure my results are common. I think everyone else I know that has had it still don't need glasses.


I got it done 10 years ago, no regressions or problems, very happy about it!


As I understand it, and I think this study concurs, permanent eye damage isn't caused by computer use.

Rather it's a combination of genetic susceptibility to being near/far sighted and straining your eyes during the susceptibility "period".

That is if you aren't genetically inclined to eye problems, no reading or computer use is going to make your require glasses. If you are genetically inclined and do near work (reading books, computers,phones etc...) then your number will rise during childhood and early adulthood. The number usually stabilizes between 20 and 30 years.

If you are genetically inclined but don't do near work, you will not need glasses.

Staring at a computer for long hours without blinking will give you headaches though, and maybe blurry vision, but that'll pass in a day or two.


I've had a lot of issues with dry eye, largely related to my computer usage. (Although it's sort of a combination of 3 factors: I work on the computer, I'm a T1 Diabetic, and I live in a dry climate. All contributors to dry eye.) At times it was bad enough that I could barely read what was on the screen, or I would leave the building and have to sit in my car for 5 or 10 minutes before driving home because the sunlight was causing enough pain to keep my eyes closed. It was impacting my life significantly.

Here's everything that I tried, along with a comment about how well it worked:

- Switched from monthly contact lenses to dailies (Helped moderately, but at that point my eyes were getting worse fast enough for me to not notice a real difference

- Switched from contact lenses to glasses (Helped with comfort once I got used to glasses again, but not with dryness)

- Various OTC eye drops (Retaine MGD is still the best for my eyes, but overuse seems to make it worse)

- Eye doctor prescribed a 2 week steroid eye drop regimen. (So no difference)

- 10 minute warm compress on the eyes twice a day (This helped a lot when done consistently, but my eyes were still really bad throughout the day)

- Omega 3 supplements (Seemed to help a bit when I was consistent with the dosage)

- Various eye exercises (helps a lot, but I HAD to be consistent for multiple days before seeing results)

- Restasis (no benefit after 3 months)

- Xiidra - okay, so this has given me the MOST relief out of anything, even consistent eye exercises. My eyes actually feel normal again, and I saw results after just a couple weeks. Using a new medication kind of makes me nervous, and it's incredibly expensive (even with insurance), but I got to the point where I was willing to take the risk because I was getting desperate. Having severe dry eyes can negatively effect every waking moment.

I'm hoping that after a few more months on Xiidra my gland inflammation and tear composition will be in a good enough place that I'll be able to stop using the medication (which I'll be following up with my eye doctor about soon).

If you're just getting started with a career on the computer START TAKING CARE OF YOUR EYES NOW. Take frequent breaks and perform frequent eye exercises. Hopefully that will help prevent you from getting to the place I did, where it takes a significant amount of work and money to get back to having healthy vision.


Thanks for all the detail. Things that I do are:

- keep at least an arm-length distance to the screen (that's what I've heard is good)

- have f.lux installed (my eyes feel noticeably more relaxed)

- make sure rooms is properly lightened, i.e. no window in front, not too dark (I have a vague idea this helps)

(FWIW, I've heard that all kinds of flat screen have a non-adjustable backlight that is supposed to quite strong. I think I read that on HN but I couldn't find references at that point.)

I wish this would become more of a well-known topic. There is a lot of information available about hands/arm ergonomics, special devices/tables and many companies have things to improve on that. But the eyes part it pretty much ignored, I don't really understand why. During the CRT screen times, you could at least choose more or less ergonomic screens. But now I feel the topic isn't there any more.


This community has an active mailing list with various experts and motivated patients: http://www.fiteyes.com


Have you been diagnosed with meibomian gland dysfunction? Did you, by any chance, ever take a drug called Accutane (Claravis/Amnesteem/isotretinoin)?


Nope, never took Accutane. I got a full examination from a specialist (including a LipiView analysis) and the conclusion was that I don't have MGD. My glands look mostly fine, and my issues stem primarily from inflammation as a result of the factors I mentioned (working on the computer, dry climate, diabetes).


Consumer Reports (Jan 2018) did not have a high opinion of dry eye medications, https://www.consumerreports.org/vision-eye-care/dry-eye-symp...

"However, both drugs are expensive and can cause side effects that can worsen eye irritation and discomfort—Restasis in up to 17 percent of people and Xiidra in up to 25 percent of people. "Judging from the clinical trials data, the benefits of those two drugs are not that much more than the risk of adverse effects,” says Marvin M. Lipman, M.D., Consumer Reports’ chief medical adviser. “Their use should be relegated to a last-ditch measure, when all else has failed.”

Yawning can stimulate tear production: https://iristech.co/yawning/


Believe me, I'm more than aware of the negative side effects and potential dangers (especially with Xiidra, which is a new medication without long term studies). Xiidra is costing me about $200 a month, after insurance. But in my case it was literally the last ditch measure, because I had tried everything my ophthalmologist suggested as well as every "home remedy" out there. (When you have severe dry eyes stuff like yawning is not going to help.)

For me, Xiidra has been the only thing that's given me relief. The side effects have been fairly minimal (stinging for a minute or two, somewhat blurry vision for up to 20 minutes) and my life is mostly back to normal now. But the cost and lack of long term studies of the medication prevent me from recommending it unless you and your ophthalmologist have determined that there are no better options.


Question: Can you still emit tears?


That sounded like one of those low-budget cable commercials for regional lawyers.


Definitely second the omega-3 recommendations. In general, eating better (especially more vegetables) has definitely improve things for me.


Manual blinking can improve dry eyes caused by extended computer use: https://iristech.co/blink-detection/

"As we stare at the computer screen or while reading, our blinkrate decreases. We actually blink 66% less while working on the computer. This can make your eyes burn, dry out, turn red or feel itchy ... research demonstrates that we do enter some sort of altered mental state when we blink — we’re not just doing it to lubricate our eyes. A blink could provide a momentary island of introspective calm in the ocean of visual stimuli that defines our lives."


If you haven't heard of the 20-20-20 rule, it is a simple rule-of-thumb to remember to look 20 feet away for at least 20 seconds every 20 minutes.

Using a standup workstation during part of the day may also help you because the "activation energy" required to move around and leave your workstation is minimal compared to sitting in a chair.

You can also get a weaker prescription if you have eyeglasses (not sure about contacts) that will help if you stare at a screen all day.


Good point on the 20-20-20 rule. There's an add-on for Firefox which I use for this below [1]. It launches a (rather invasive) fullscreen popup reminder every 20 minutes. Far from perfect, but better than using a loud timer or relying on your distracted brain!

[1] https://addons.mozilla.org/en-US/firefox/addon/eye-strain-pr...


20 is arbitrary, but it integrates finely with the Pomodoro Technique: https://cirillocompany.de/pages/pomodoro-technique


Any recommendations on physical (non-app) pomodoro timers?


Just searching around. This may be a little too large but I like the combination of visual and adjustable auditory indicators.

https://www.timetimer.com/collections/timers/products/time-t...


Thanks for the pointer, that is a good combo.

UX of this multi-timer looks promising for tracking different classes of activity, but I haven't tried it yet: https://www.amazon.com/gp/product/B004S56RJG/


The pomodoro technique was named so because the kitchen timers tend to look like a tomato. We've come full circle :)


One set of of anecdata from the suny end of the spectrum: I have been staring at computer screens since 1982. For the first several years those screens were mainly crappy small televisions attached to Orics and C64s. I was lucky to have really good eyesight in '82, and I am lucky to have it still, although these days, nearing sixty, I do need glasses for reading screens and paper. I can still manage without, but that ends in headache within just a few minutes.

I buy those cheap standard supermarket glasses, currently at strength +2. They get me nicely through 8 to 10 hours af screen in a day. Whenever I go off the deep end, and spend more hours than that for several days running, I do tend to get reddish, itchy eyes.

As others in the thread have reported, the arrival of flat screens was a blessing. CRTs would generally tire me out quite a bit sooner. But I don't seem to have suffered long term adverse effect from them.


I'm the same. Also been staring at computer screens since 1982, with no obvious problems. Getting old is annoying though: my arms are now not quite long enough to focus perfectly on my phone screen without my reading glasses, but a +1 pair of supermarket glasses is enough to fix that. Distance vision is still fine.

The great thing about LCDs is that even in my 50s I can place them far enough away to use without even needing reading glasses. CRTs were so bulky, it was really hard to do that (but back then, I didn't need to).

Anyway, just another datapoint that intensive screen use for 3.5 decades doesn't have to cause issues.


> a +1 pair of supermarket glasses

+1? Those were the days!


I've been staring at screens since I was 10 and always had perfect[0] eyesight.

Had is the keyword here, because two years ago I began spending around half of my time in a place 1500km away from my home, to and from which I drove, because I needed to both have a flexible schedule and bring with me items that I couldn't or didn't want to bring aboard a plane(like my guitar). Also I despise flying.

After a year of those 17-20h drives back and forth I started experiencing symptoms of dry eye syndrome which eventually developed into styes, and later a total of three chalazions.

Recently I had a checkup done and while my left eye is still good(insignificant defect), the one that had chalazions is currently -0.5D with 0.25 astigmatism.

My point being: It took only two years of extremely long driving vs 17 years of staring at screens to cause eye problems in my case.

[0] When I was 17 I could easily read time from a 30cm high LED display from 120m.

EDIT: emphasis.


Did eye doctors have a theory for the connection between dry eye and driving? How many breaks did you take during the 20h drive?


My doctor said those chalazions are "no accident", but I'm not sure what she meant by that.

I think it usually amounted to around five 15min breaks - mostly to buy vignettes for each respective country I was driving through and to fill up.

After around 18,5h of driving I had to take naps in order to avoid falling asleep at the wheel.

Needles to say I don't do those marathons anymore - it's obviously dangerous and bad for my health. I break up this trip into two days which makes a world of a difference.


Speaking of eye health, I wonder what effects programs like f.lux and their newer built-in alternatives have. Despite a bit of trepidation when first giving it a try, after a while it feels very natural.

Since ebook readers have become more commonplace in the last 20 years, I also have to wonder what effects that might have on us. Even on days when I avoid using my computer, I still spend a good couple of hours reading ebooks on a tablet.

There have also been tons of advancements in technology. I don't think high-DPI displays were commonly available, but the technology is increasingly commonplace, especially on mobile devices.


Note that many tablets support things equivalent to f.lux. Apple tablets do, I believe. So does Surface Pro and probably many other Windows based tablets [1].

A lot of people claim that the Kindle Paperwhite does not need it because the display is not back lit. (The lights are on the edge, and there is a transparent light guide in front of the eInk display that directs this light so that it shines on the eInk from the front and reflects off it to you).

This seems like complete bullshit to me, because I can not see any way that the intrinsically photosensitive retinal ganglion cells in your eye could possibly tell if photons come from a front lit display or a back lit display. All they should care about is the wavelength and the intensity.

That's not to say that the claims that the Paperwhite doesn't need a reduced blue light mode aren't true--I'm just saying that if they are true it isn't because it is not back lit. It would be because they are using a light source with less blue, or the eInk display absorbs blue so that it does not reflect much blue from the light source.

Speaking of reducing blue light at night...I've wondered if what is important is the absolute amount of blue light or the relative amount compared to daytime levels. The intrinsically photosensitive retinal ganglion cells signal the suprachiasmatic nucleus (SCN) in the brain with the amount of blue light they are receiving. The SCN responds to changes in that to control circadian rhythms.

If the SCN is just watching the levels and looking for them to cross certain fixed thresholds, then at night we'd need to make sure we drop blue light below certain absolute levels.

If, on the other hand, the SCN is looking for relative changes, such as blue light dropping to below some percentage of the peak over the last 12 hours, or over some kind of average over the last several hours, then instead of working to eliminate blue light at night it should be possible to achieve the same effects by increasing blue light during the day.

So instead of trying to find software to reduce the blue light on every screen in my house (an increasingly hard thing to do as more and more things have screens), I should be able to install lights that have very high blue levels and have them on during the day, to push the blue light threshold high enough that when I turn those lights off I am below it even though my TV and other screens do not have low blue light modes.

[1] Windows in general supports it, but I believe it requires some support from the GPU, so whether or not it works on a particular tablet depends on the hardware.


This page links to research on blue light effects, https://glarminy.com/2016/04/11/are-your-eyes-sensitive-to-l...


Don't know it is has any effect health-wise, but it is still very comfortable.


I wonder how many of this have change with now monitors being LCD LED, CCFL or even OLED instead of the traditional CRT. Specially in the "Radiation Emitted" department.


"Although some of these problems may not result in symptoms under less visually demanding conditions, the high demands of computer work cause them to become manifest. "

THIS. After about 7 years of staring at a screen all day at work, then coming home and staring at a screen all night (gaming, programing, etc), plus marijuana = dry squinty eyes-- the cumulative effect was that my eyes began to always focus slowly and unevenly, especially on things far away.

I got glasses and they helped, but it felt like more of a bandaid than a solution.

I have since reduced my close-up computer screen usage dramatically. I also do the occasional eye exercises (youtube has a lot of these and they really help).

I stopped wearing glasses and spend more time outside and away from the screen so my eyes actually have more things to do than look at bright pixels 3 feet away.

If I could give any advice to my younger self it would be to minimize long stretches of staring at the screen. Take plenty of breaks to give your eyes a break.


What worries me the most is the fact that monitors and phones are outputting light directly to our eyes. Almost everyone, at least in the U.S. has both computers and phones and those devices output light directly to our eyes. Where as, even in 1997 most people weren't spending all of their time looking into light. We were looking at things with reflected light.

Somehow I think this direct light into our eyes is impacting our not only our eyes, but our brains negatively.


I always adjust to the minumum brightness needed for my eyes to see can See comfortably. The monitors and phones have a very bright default value, on my LCD I practically have contrast and brightness near 0. Same with my phone. Everyone is different, but I would adjust the brightness to match the exterior lighting so they balance. Most people have the screen too high in comparison to the background lights.


Been using computers for 21 years. I got some floaters when I was a teenager, but still 20/20!


"Got some"? My ophthalmologist says that everyone has them. Some of us are just 'lucky' enough to notice they exist.


do you have good teeth? e.g. never had braces pulling on the interior fascia in your skull?


Personally for me, I have got more back/shoulder problems from long term computer usage than eye primarily due to bad posture. Though I do wear glasses, but my prescription hasn't changed in the last ~10 years.



Do you know the color temperature of that film, e.g. how does it compare to using flux, redshift, etc?


I'm not an optics expert. I have used Flux and haven't used Redshift.

I much prefer the Rose screen to Flux. Flux changes the colors but, sorry I lack the English to articulate this properly, the screen makes all light less "harsh". This is most visible when looking at a white background. Even with Flux on the rose tinted is much "softer" and easier to look at than the same screen without.

FWIW, a neurologist recommended the screen to counteract excessive optical stimulation from computer use.

I've stopped using Flux in favor of this screen, even at night.


I'm in my 20s and I have dry eye and it has significantly affected my life. I wish I had known about it when I was younger.

Some background: eyes are lubricated by the tear firm which consists of three layers: inner mucous layer, an aqueous solution layer, and an outer lipid layer (meibum). The mucous layer is the thinnest and keeps the tear film to your eye. The aqueous solution is released from the lacrimal gland and makes up the bulk of the tear film. Meibum is secreted from meibomian glands in the eyelids every time you blink and keeps the tear film from evaporating. With a healthy tear film you should be able to keep your eyes open for at least 30 seconds before you start feeling a burning sensation. If you don't have a stable tear film you will start to feel a burning sensation much sooner and this is what is known as "dry eye". Dry eye and can be caused by a deficiency in any of the three layers and is usually categorized into two main categories: aqueous-deficient dry eye and evaporate dry eye. Aqueous-deficiency dry eye is usually caused by systemic diseases such as autoimmune diseases (e.g. rosacea, lupus, Sjogren's syndrome) that prevent the lacrimal gland from producing tears and from the statistics that I've seen this accounts for about 20% of dry eye cases. Evaporate dry eye is caused by a deficient lipid layer which is usually caused by meibomian gland dysfunction and accounts for the majority of dry eye cases.

There's not a lot known about what causes meibomian glands to malfunction but some theories are that: inflammation causes them to get blocked, autoimmune diseases attack the tissues, hormone imbalance causes deficient secretions, harsh environments cause inflammation which causes them to get blocked, and contact lenses interferes with blinking rates and the mechanics of blinking. Once meibomian gland dysfunction starts, it often starts a vicious cycle which causes inflammation which causes more blockages which causes more inflammation. Blockage of the meibomian glands eventually (think several years) leads to meibomian gland atrophy where the glands start shriveling up and die, starting from the back. Healthy glands are normally about 10 mm long but over time they will become truncated and eventually completely atrophy (known as "gland drop out"). This process is also seen to a lesser degree in elderly people, and especially postmenopausal women.

I started wearing contact lenses when I was a young teenager, and also as a young teenager, I spend an unhealthy amount of time staring at computer screens. A few years later my contact lenses started to become uncomfortable and I switched contact lens brands and cleaning solutions and I was able to continue wearing them for another couple of years. Eventually it got to the point where I couldn't tolerate wearing them because they were just too uncomfortable. I figured this was normal because lots of people complain about their contact lens comfort, and I attributed it to living in a dry climate and spending lots of time on the computer. But then, even with wearing glasses I started noticing that my eyes were uncomfortable. I started waking up with red, gritty eyes. I went to my optometrist and told him about this and he simply gave me some eye drops and told me to put them in before bed and whenever I felt dry eyes. But over the years problem only got worse. I had to constantly blink, and my eyes were always bloodshot. This is when I started to seriously investigate dry eyes.

I went to an optometrist seeking for help who told me about some things I could try such as warm compresses (which I was already doing) and blinking exercises. I also went to an ophthalmologist who basically told me that lots of people have dry eye and bluntly told me "I deal with people who are about to lose their eyesight, and you are not going to lose your eyesight because of this" and prescribed me a short course of corticosteroid drops. I saw a couple more optometrists who were of no help, before I decided to seek a dry eye specialist in another city, who looked at my meibomian glands and confirmed what I feared the worst: my meibomian glands were in very bad health. I was only in my 20s, and my meibomian glands had already truncated to about 25% of their original length. (You can see how healthy glands are supposed to look compared to unhealthy, truncated glands: http://www.clemsoneye.com/Portals/0/meibomian_glands.png)

I found a supportive optometrist in my city who is sympathetic and willing to try different treatments with me. So far I have tried the following:

* Lubricating eye drops: I take preservative-free drops every day but they only offer limited short term relief. I've also tried lubricating gels but I find that they clog my glands even more and cause more discomfort. I only use them in emergencies when I'm willing to trade off short term comfort for more misery (they will unbalance up my tear film for several days).

* Warm compresses: Applies heat to your eyelids to unclog the glands. I do this once every few days but if I do it any more I will end up with more inflammation which makes my symptoms worse.

* Corticosteroids: They do seem to reduce inflammation but doctors won't prescribe these for more than a few weeks at a time because they cause high intraocular pressure.

* Tetracycline antiobiotics: Low dose tetracycline antibiotics (usually doxycycline, minocycline) are taken off-label to reduce inflammation. I've been taking these on and off for months at a time for the last 5 years. I believe it helps my comfort but my optometrist warns me to not stay on long term, but I will continue taking these for the rest of my life because at this point I don't care if long-term antiboitic use destroys my kidneys and liver.

* Restasis: An eyedrop that helps primary for aqueous-deficient dry eye. I've been on this for a while as well and I will continue to take it even thought I don't think it helps much. It's normally very expensive but luckily my insurance covers it.

* Lipiflow: A treatment where a machine places a cup on your eyeball and applies heat and massages the inside of your eyelids. I spent $1500 out of pocket on this and it was just as effective as my next item.

* Manual expressions: Using forceps my optometrist squeezes my eyelids to force meibum out of my glands to keep it from clogging and stagnating. This helps short term, but it can only be done so frequently because it can cause long-term tissue damage. I purchased my own forceps and (probably to the horror of my optometrist, I never told him) I do this myself.

* Controlling environment: Having a humidifier helps me a lot and I keep the relative humidity above 80%. Being in a dry environment such as airplanes is very uncomfortable and whacks my tear film out of balance for days.

* Moisture chambers: Essentially, these are air-tight goggles that prevent moisture from evaporating from your eyes. They do help but I hate having to wear them and I don't wear them in public, but I will probably have to eventually.

* Eye exercises: I consciously blink hard several times, every 30 minutes. It helps a bit.

Overall, my symptoms have only marginally improved. My life has become miserable because of this and my social life and professional life have suffered. I don't enjoy going out anymore because I hate being in dry environments where it causes my symptoms to get worse. Just being in a dry environment for a couple hours will disrupt my tear film for days after. It has caused me depression and I considered ending my life at one point.

There is a lot unknown about this disease. Nobody can tell me why my glands got into such bad shape, but I believe wearing contact lenses and using the computer, and having bad blinking hygiene contributed a lot to it and I see that even most optometrists have been clueless and are only now learning about dry eye because of its increasing prevalence. Because it's not understood well, there's not much support for sufferers of dry eyes. The immediate reaction of optometrists upon hearing a complaint about dry eye is "here, try this brand of sample drops that they sent to my clinic". Insurance doesn't cover treatments and I've incurred thousands of dollars in out-of-pocket expenses, and had to take significant time off from work to seek specialists and treatments.

Looking back, here's what I wish I had done:

* Not wear contact lenses, especially when on the computer for 12+ hours a day

* Blink regularly and consciously when using a computer

* Investigated sooner about dry eye when I started experiencing symptoms (it is not normal to have dry eye)

* Spend more time outside

Perhaps how previous generations were taught about oral hygiene and the importance of brushing teeth, future generations will be taught about ocular hygiene and the importance of blinking exercises and health of eyelids.


Previous thread mentioned (a) gel drops (b) googles with airtight seal to reduce evaporation (c) taping eyes shut during sleep to reduce evaporation and (d) discussion forum for dry eyes, http://www.dryeyezone.com/talk/

https://news.ycombinator.com/item?id=7480946

Yawning might help, https://youtube.com/watch?v=I0dQx4SNSwE

If the monitor is lower so that you are looking down, more of the eyes will be covered by the eyelid, reducing evaporation.




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