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  • mvanier Level 1 Level 1

    I haven't posted for a while, but I have some new information that might be interesting to some of you.  I got a Dell U2413 monitor because it was measured to be PWM-free for all brightnesses above 20, and even below that the PWM frequency is so high that I doubt anyone could detect it (over 8000 Hz).  It also has the GBr LEDs (green + blue with red from a phosphor) which sounded interesting and which supposedly gives better color than normal white LEDs (blue + yellow from a phosphor).  I'm using it with a new Macbook dual-booted with Mac OS X and Ubuntu so I can control for temporal/spatiotemporal dithering (Mac OS X uses it, Ubuntu doesn't (at least on Intel GPUs)).  This has been a very interesting experience.  The first things I noticed were that the color really is much better than typical white LED backlights, very rich and vibrant.  Also, the flicker, if there is any, is not annoying and is certainly no worse than what I've experienced with CCFL-backlit monitors.  That left me with two potential problems: dithering and blue light (color spectrum).  When I got the monitor my eyes and brain had already mostly adjusted to the dithering to the point where it really wasn't bothering me much, but I was still getting eyestrain, which I assumed was from the blue light spike.  Using F.lux (Mac OS) or Redshift (Linux) made a big positive difference, which confirmed it.  What I've discovered is that the different eyestrain triggers cause very distinctly different kinds of eyestrain.  Eyestrain from PWM or dithering is experienced as aching eye muscles, because the flickering makes the eye move around a bit trying to follow the flicker.  In contrast, eyestrain from blue light spikes is experienced as a sore, burning sensation in the eyes.  But here is the really good news: over a period of weeks, the eyestrain has simply faded away!  My eyes have adjusted to the new monitor.  It's not complete; I still need to use F.lux/redshift for comfort, and at pretty strong levels (F.lux at about 3700K is the most comfortable currently).  But I don't have any problems using the monitor anymore, which is great.


    I think the lesson is this: the eyes and brain are very adaptable, and can compensate for a lot of variation in light sources.  When people get cataract surgery, the new artificial lens that is implanted is completely clear whereas the original lens was generally very yellowed.  The patients initially see everything as way too blue, but over a period of about three months their eyes adjust and things look normal again.  I think this is what is happening here.  The light from CRT monitors didn't bother me because I'd been watching CRT televisions my whole life.  Fluorescent lights were the same story.  In contrast, white LEDs have a light spectrum my eyes had never seen before, and I obviously needed time to adjust to that.  I recommend that people with this problem start using the monitor for no more than an hour a day until they adjust, then increase the time gradually.  It seems that the dithering problem can be compensated for even faster than the light spectrum problem, since after only a couple of weeks that didn't bother me either.  I don't know about PWM; it's possible that PWM is such a gross effect that some people can't learn to ignore it, but since there are lots of PWM-free monitors out now, why not just get one of those?


    The only other thing I did is to start taking cod liver oil supplements (in moderate doses; large doses can be harmful!).  This was just to make sure that my vitamin A levels were good, since vitamin A is a precursor to retinal, the primary visual pigment.  I have no idea if this helped, but it didn't hurt.

  • Jessiah1 Level 1 Level 1

    Mvanier, I also take fish oil supplements twice a day (For about 2 months now), there is research that points to fish oil helping keep dry eyes from going dry. This would definitely help those with that issue if it was part of their problem, no real help for me there however fish oil also helps with inflammation so there is a possibility it helps with headaches through swelling reduction in the brain? It is a tricky supplement and people should speak with their Dr. before using to get accurate amount and type recommendations, some are not processed well so a little research goes a long way when considering supps. Your Dr. may feel a higher than recommended does is needed for results as well.


    Also, it sounds like the monitor is using similar tech. to the Sony triluminos display and could be reducing the amount of blue light emitted, would be really helpful if someone had a good spectrometer to measure this with all the different devices and post the results.


    Does anyone know if there is a cell phone in the USA with a triluminos display?



  • crazypicard Level 1 Level 1

    I was eating 2 cans of sardines everyday for awhile. That equaled 3 grams of Omega 3 a day. It's supposed to help with dry eyes. I didn't really notice much of a difference. The two biggest things that have helped me Is vitamin B2. It's helped with reducing the migraines. Bilberry I think was the greatest Improvement so far. Although all of these things only help a little.

  • tfouto Level 1 Level 1

    Jesse, Sony Xperia Z2 has this tech. Is not yet available, but should be really soon. This month or maybe early April.


    mvanier: thanks for the sharing.

    I believe it's possible for the eyes to adapt, to a certain extend. If the monitor is too agressive in blue light, simply it's not possible...

  • peter_watt Level 3 Level 3

    Blue light and UV can be completely blocked with suitable yellow lenses such as ski glasses, if that is the cause. 

  • luisx Level 1 Level 1

    I had my beloved iphone 4 for nearly 4 years and has been like an oasis in this terrible times where I couldn't look into any new led screen. I've had 7 laptops bought and returned over the last 3 years and a handfull of monitor with the same luck... (and 3 televisions too)


    So, last friday I upgraded my phone to IOS7 and since then I can not look at it for even a minute! Go and explain that. Obviously the screen was good as I could use it for many hours during 3 years. Great phone with ios 5. There is for sure a software and driver issue to blame in here. Idiot of me, late I found many forums with users reporting the same and advising not to upgrade. Now here I am with an unusable phone. To my surprise it is technically impossible to downgrade again, even with jai.b.eak options. I am so disappointed, this is unaceptable. Now apple I hat.e you! Why did you do that to me??? Certainly it is over between you and me, never again a product from you. Enough


    I am looking forward to hear from anyone that can mention a tolerable phone. Does the experia trilumious work well?? Will the z2 be worth waiting? Any other brand recommended?


    Thanks for listening to my frustration,



  • tfouto Level 1 Level 1



    I guess old phones would be better. I will wait for the Z2, to see if it will be ok. That's what i hope, but i dont know.

    Xperia Z1, i think already is triluminos but technology is not advanced.


    So i guess wait for Z2, or go to an old phone. Maybe Android who dont have updates, or you can choose not to update.


    Can you lower the brightness and contrast on ios7 and see if it helps a little?

  • spprt Level 1 Level 1

    I have the same problem. iOS 7 basically destroyed my iPad 4, which I cannot use anymore. I don't know what to do.

  • LovesDogs0415 Level 1 Level 1

    Luis, I absolutely understand because it happened to me when the iOS 7 came out.  I even found a compassionate Apple guy who tried desperately to find me a phone with the old OS.  I had to use the phone and decided I'd just use it for emergency things.  Every other phone type I tried was worse! 


    Now I know that this issue is related to more than brightness, but try this.  I turned the brightness down so low that the slider is between "g" and "h" above the words Auto-Brightness on the Wallpapper & Brightness under settings. 


    This allows me to use the phones features that I need and I don't have the trouble I used to have with strain and headaches.  Admittedly, this may not work for you.  I am SHOCKED it works for me, but it does.  Brightness adjustments have no effect on any other device and my Apple computer is so old I'm scared.   I am four OS systems back on my computer.  LED lights make me nauseous, and the LED TVs are not an option at all.  I don't go near the TV section in electronic stores and I don't go near the Microsoft store after becoming very ill visiting with my husband to buy his tablet. So many devices with that trigger light source!  So, I am definitely affected by this "phenomenon" whatever it is, but this works for me.


    Good luck.

  • StefanD13 Level 1 Level 1

    I use as well an iPhone 4 (bought Nov 2010) and is very comfortable to use. Even after the iOS7 update...

  • Karoozo Level 1 Level 1

    2008 macbook pro led backlit - no issues

    2012 mba - eye strain, headache.

    Where is the problem? Glossy screen?

  • mvanier Level 1 Level 1

    Karoozo, you might want to look at the huge backlog of posts in this mailing list to get an idea of the possible problems.  But my guess would be that you are reacting to the spatiotemporal dithering that is a "feature" of newer macbooks, since you've already had an LED backlit macbook that didn't bother you.  If you look at the screen and it seems like the letters are a bit indistinct and the background looks a bit like "snow" (random noisy pattern like on a TV that isn't getting any input) then it's definitely the dithering. If so, the odds are that you will be able to adjust to the new macbook over time; your brain will learn to tune out the dithering.  I'd recommend not using the new macbook for more than an hour at a time until you adjust.  My new macbook caused me intense eyestrain when I got it, and now I can use it all day without problems.

  • Scott98981 Level 1 Level 1

    I found something curious. I have no problems with any iphones on any iOS. However I tried the new iOS7.1 accessibility feature "reduce white point" and instantly it feels like the same eye symptoms I get from other devices like the iPad air. When I turn it off, I'm back to being able to use the iPhone 5 or iPad 3 all day. This suggests to me on some levels at least that the OS can affect the experience we are having. I wonder what the software is doing.

  • luisx Level 1 Level 1

    Where do I find that option? Just upgraded it and can't see reduce white point (my UI isn't in english but still I can't find an equivalent setting)

  • peter_watt Level 3 Level 3

    Settings, General, Accessibility, Increase Contrast,