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  • tight_eye Level 1 (0 points)

    @mvanier: Interesting but I'm not really sure that we suffer from that. Is there a way to make the dithering more visible? I feel that it is so latent, that you only can see and feel it if you are really sensitive to it.  Maybe I have to try out Linux.


    What I can say on base of my observations:


    - by far the worst display is the retina

    - bad but better is MBP

    - best of these is MBA (possible to work with but headache causing)

  • tight_eye Level 1 (0 points)

    PS: I should mention that I personally just have problems with reading and writing text on all macbooks. If I watch a fullscreen video on youtube oder look at images, my eyes seem to feel fine. To me this is a clear sign that it has nothing to do with dithering does it? I would say it mostly sounds like poor eyesight but I have 20/20. This is really strange.

  • mvanier Level 1 (0 points)

    @tight_eye: I can't guarantee that dithering is the culprit, but it could definitely be. One reason you need so many colors is to generate smooth color gradients without any banding.  Laptop displays usually aren't that high quality (usually 6 bits per color) so dithering is used instead of forcing the consumer to pay hundreds of dollars more for a true 8-bit display.  As for text, it is definitely a problem with the snow effect because the contrast is so high that the problem jumps out at you.  Videos are less of a problem for me too, though I still notice it.  Note that the eyes are much more stationary when reading text than when viewing videos, which makes a difference. Of course, most people never notice any of it.  Anyway, nothing you've said makes me think that it is not dithering, though there is always the possibility that it is a similar effect used for a different purpose.


    Have you tried using the computer for an hour or so a day maximum and then gradually stepping it up?  Your brain may be able to tune out the snow noise over time.  That's what I'm experiencing.  It ***** that we have to do things like this but Apple so far hasn't given us a choice to turn the effect off.  That would make a nice accessibility option, easy to implement, assuming Apple cared enough to do it.


    One thing more: I find that the snow effect causes a very distinct kind of eyestrain, with a lot of diffuse aching of my eye muscles and dry eyes.  PWM, in contrast, causes my eye muscles to hurt in a different way, like my eyes were continually being jerked in the same direction.  And high blue light just makes my eyes sore.  I wonder if other people feel the same thing.

  • tfouto Level 1 (0 points)



    i feel different kind of eye pain depending on the monitors, for sure.

  • tight_eye Level 1 (0 points)

    @mvanier: Makes sense, I noticed my eyes jumping around in Videos which is more comfortable than just staring.

    To describe my eyestrain: I just see snow everywhere. The problem for me starts right after turning the rMBP on. I notice it immediately. Everywhere white particles sparkling around. My eyes feel strained, tensioned and dryer when I use the MB longer. Eyes feel sore und very heavy. They lose the ability to focus and are just crying for relax.


    When I shut down the machine unfortunately the snowy vision does not go right away. It kind of transfers to my normal vision which is very annoying. Today I did not use the MB but I'm still suffering from the snowy vision from yesterdays work. I need tons of sleep when I use MBs. In the morning I nearly cannot open my eyes because they feel so tight und tired. It is just that bad. Even 12 hours of sleep do not solve this problem.


    Regarding PWM I cannot add anything.


    BTW: Are you sure the iPhone does not use dithering? When I reviewed the last years yesterday it got clear to me that I feel tired every morning. Sometimes I got a tad of snowy vision on the iPhone too. But it is just very minor, cause the screen is very small.


    And can you recommend a useable laptop for us? I'm struggeling to find an adequate working machine. I partially work as a journalist and graphics artist on a computer. I only need a good computer not causing so much ache. Only. Is this possible?

  • tight_eye Level 1 (0 points)

    Sorry to make a new post again but did I mention that I have severe problems with iPhone 5 and iPad 3 too? This is close to be the same like the retina eye strain. Do iPhone and iPad use PWM and/or dithering? Maybe noob question but it's just not my kind of business as I'm more forwardly looking for a pleasing solution no matter what it will cost or require.

  • tight_eye Level 1 (0 points)

    By the way I would also be interested in your experience with dialing down the gamma on the macbook. It's kindly explained that this setting manages the overall contrast und I have set it to 1.0 instead of native 2.2. Display looks completely rubbish now but for my eyes I can note a bit better experience now. I'm close to being sure that the overall contrast has a big influence on this problematic situation.

  • mvanier Level 1 (0 points)

    @tight_eye: My understanding is that the iPhone 4, at any rate, doesn't use temporal dithering but may use spatial dithering (which should never cause eyestrain).  I have no experience with the iPhone 5, but many people who have no problem with iPhone 4 have reported problems with the iPhone 5, so the 5 may be using temporal dithering (or have some other problem).  Re laptops the situation is pretty hopeless.  Laptop screens are not very good in general in my experience.  The best bet is to get a flicker-free desktop monitor and use that connected to your laptop.  Unfortunately that won't fix the snow problem since it's a software artifact, not a hardware one.  Switching to Linux may help with that (if that's an option) since I don't see snow on Linux (with Intel graphics chips, at least; no guarantees with Nvidia or Radeon).  I don't know much about Windows; I've seen snowy displays on some Windows computers but Windows tends to offer more options than Mac for adjusting the display.  Re dialing down gamma: you want to install the f.lux software; it's free and does a much better job of dialing down gamma than can be done manually.

  • tight_eye Level 1 (0 points)

    @mvanier: Thanks for the response. The thing is I need a Laptop for work and cannot pack up a huge Monitor when I do work on journeys. Linux could be an alternative, but I would have to find out how to install it.

    Dealing down gamma is preventing high contrast eye strain, f.lux just deals with the colour temperature and not with the contrast. But I have to report, that the gamma try did not work for long. It must be another problem. Still PWM and dithering possible or my problems.


    It seems like we just have to try out randomly new devices/laptops and hope that it works with our eyes. As mentioned I cannot report problems with my old Vaio and I have no clue whether it uses PWM oder dithering so far. **** bad.

  • Rubydiamond Level 1 (0 points)

    After waiting to buy a new macbook for the last few years, I finally got the a new MacBook Pro this week.

    Its not retina display, because I'd heard people had some problems using Photoshop with the retina, and I wanted to avoid that.

    I'd been using my old Mac PowerBook,  a friends 2008 Macbook, and an ipad2 with no issues.

    What a shock I encountered when I used my new macbook.  Within minutes my eyes felt weird and I ended up getting a silent migraine (the visual disturbance without the headache).

    I wondered if it was all in my imagination.  So I tested it several hours later, using my ipad for a while and then turned to the new macbook.  Boom, my eyes started feeling "jumpy", uncomfortable, and I'm couldn't keep looking at the screen.

    I returned my new macbook right away because I didn't want to be stuck with it.

    I have been a mac user since the 80's and this is a terrible disappointment. 

    I appreciate the comments here on what might work, so I will have to turn toward an older second hand mac but I worry about my future as a mac user.

  • tight_eye Level 1 (0 points)

    Yes this was also a big disappointment for me too. Unfortunately it seems not only to be Apples fault. As I have already reported a brand new Lenovo Laptop from late 2013 also gave me severe symptoms.


    I found an older post in this thread where a mid '09 MBP and mid '10 MBP were two times confirmed not to cause any strain or discomfort. Can this be confirmed by more people? I will take a close and willing to buy look to these older machines on eBay and I want to make sure that I can keep it then. The potential need to resell it again when symptoms occure without the opportunity to just give it back is more problematic und will cost money each time.


    Are there more MB which don't cause any symptoms? Prefereably any Macbook Air?



  • tight_eye Level 1 (0 points)

    So today I just started to install W7 via Bootcamp on the Late 13 rMBP and see if this makes any difference. I had no problem with windows 7 ever, so I can find out whether the OS or the hardware is the problem. In terms of dithering I actually wasn't able to find out whether I can disable it on W7. Does anyone know whether Smart Image Dithering on W7's IE is the crtical thing? I found out that it can be deactivated. 

  • tight_eye Level 1 (0 points)

    Well I managed to get W7 installed via Bootcamp. I had to try it three times but now it is working. What can I say. The rMBP Display seemed magically to change a lot. Now it is much more pleasing on the eyes but the lowest brightness setting still is a bit high for working in lowlight situations imo.


    I have absolutely no idea what exactly is responsible for this dramatic comfort improve but I am impressed. One thing I noticed is that the colours look different. Where Mavericks renders a muddy, reddish white, the whites in W7 seem to be close to perfect. Second reading and writing on this display is not longer a pain in the *** because the black and white contrast does not seem to be as harsh as in mavericks. From a technical pov I know that what I say is barely impossible at least when it comes to the hardware.


    My conclusion is that a huge, if not the most, part of this whole problem is software related. I only notice a bit of a headache when looking at the screen now but just a very minor sign of eye strain at all.


    This is just amazing.

  • OQ3 Level 1 (0 points)

    The only things that come to mind with software influencing the monitor as in creating or reducing something that has an effect on eye comfort are 1.backlight brightness change (1a. PWM duty cycle change) 2. brightness change through pixels 3. changing color spectrum through pixels 4. changing PWM frequency of backlight 5. making pixels flicker. I believe the only likely thing is pixel flicker and I highly doubt it is caused by standard temporal dithering (since attempts of deactivating it didn't result in any relief). 1 & 2 I cross out because brightness has been attempted to be adjusted by the user. 1a & 4 I cross out because it is likely Apple doesn't use PWM anymore. 3 I don't think has that strong of an influence. We have seen 5 happening on youtube videos. I think we need close-ups of pixels of problematic devices with quality cameras and experimentations with different camera and monitor settings, such as shutter speeds, monitor brightness, looking at different colored pixels of the screen etc.

  • mvanier Level 1 (0 points)

    @OQ3: Actually, on my Macbook I found that using grayscale and very high contrast provided significant relief, which certainly seems to support the dithering theory (not much fun to use the computer that way, though).  When the contrast is high enough all pixels are either all black or all white, so there is nothing to dither.  I know of no other way to turn off dithering in Mac OS X, though there may well be ways in Windows and there are definitely ways in Linux.  Nevertheless, I'm all for getting close-ups of pixels of problematic devices with high-speed cameras.