ravipra Sorry I am excited and editing after you replied and screwing up the flow. I made the changes and will test further. If you could look at my last response to make sure we are using the same settings otherwise I would appreciate it. What time zone are you in? I am in central US time. I will test tomorrow and the next days and am crossing fingers this works. I wish there was an objective test I could do as well to see if this DOES turn off dithering and be sure. It would be incredible if dithering was the problem and it was this simple to shut off in linux.

A related thought...some people have noticed new Gmail and Firefox etc to be more straining on an otherwise good device. IF that is due to those apps specifically dithering, I wonder if this setting will override that, or if we need to find a way to shut off the apps dithering instructions individually.

    @hpst

    The other changes are to minimize the kernel overheads:
    norandmaps nokaslr - disable address randomization which is a security feature
    audit=0 - disable kernel auditing
    cgroups_disable=memory - disable cgroups for the memory subsystem (something like a quota system for memory used by the processes)

    1. I tried using redshift several times. initially it felt good, but using it for few hours gave me strain. So, gave up on that line
    2. Again I tried changing it using xgamma. The experience was similar to redhift. So not doing anything now.
    3. I am not sure what is none-strong scale, but I used to fiddle with hinting a lot, but never needed to do that I after shifted to Manjaro KDE. The output of "xrdb -query | grep Xft" for me is:
      Xft.antialias: 1
      Xft.hinting: 1
      Xft.hintstyle: hintmedium
      Xft.rgba: none
    4. Since mine is a 6-bit panel, I thought a maximum value which is less than or equal to (6 *3) would be good and tried that, 3 being for the three channels (rgb).

    Yes, a majority of my symptoms (strain, inability to focus) are gone. But like I said, it might be a cumulative effect. If this itself does not work, I can compile and post all my settings.

    I am in IST (India) timezone.

    Sure, I will keep checking this thread and post what I could.

      ravipra . If this itself does not work, I can compile and post all my settings.

      Thanks for all your help. Yes please do post all your settings as soon as you can. I'd like to make the exact same changes you did, and if it works then remove things one at a time and see if that narrows down key elements.

      I have a bad habit of getting excited when there is some new possibility of hope so am trying to restrain myself, but if this works for others as well as it did you this will be a major breakthrough and one that is very simple to implement. We'd then just need to figure out how to translate it to those with Windows and MacOS as well since most people use those.

        @hpst you are welcome! I too am looking at an objective way. Tried to use a cell phone camera in slow motion etc, but to no avail! Hopefully we all together can find one.

          ravipra You might want to make a new post just for your theory and instructions when you have them ready. Something like "Linux users please test these settings that helped me" etc. That way we can consolidate all results and questions there.

          Another user @JTL is working on some dithering stuff and should have some good input on this when he is on next. I really hope your idea works as I need a linux solution badly so the timing is perfect.

            Does anyone have an idea how strong the temporal dithering flicker might typically be? Surely it must be very low? If we have 256 colors for each subpixel and look at grey scale flicker, the lowest flicker percentage could be as low as 1/256 = 0.39%. Which means we could react to 0.39% ripple flicker. That seems incredibly low. The real life value shouldn't be too far away from this? Like, a dark grey with RGB value 64/64/64 could flicker 4 times stronger but at 1.56% would still seem pretty low. Thoughts?

            • hpst replied to this.

              KM The only time I have "seen" it is in the Dasung videos but who knows if that display is translating how it actually looks on an LCD that is more capable? On the Dasung's it looks like wiggly maggots and not very fast. But I also don't know that it really matters since looking at any image that you think is static, but its constantly wiggling, can't be comfortable for the visual system to parse I'd think. I have said before if dithering is the issue I think its more the movement of what is displayed, even a white background, than flickering that's an issue. That may sound like a pedantic difference but I mean that flickering is just "on/off" of a point in a regular frequency and happens all around us even in incandescent lighting....apparent movement of the elements/background is a different thing and adds complication to what the brain/eyes have to process.

                @ravipra I am not seeing any super obvious relief with just the one GRUB setting change on my painful laptop. I haven't used it for a long time but it's still a harder to look at than my 12yo CCFL laptop just at first glance, but it's also hard to trust subjective opinions in the short term as I am afraid of this bad laptop anyway and don't know if symptoms are real or imagined. I'd really like to see how it is with an identical setup to yours. I have a 16.04 iso of Manjaro KDE but have never used it...though I don't see how that should be different than KDE Neon for this issue. Was the difference obvious to you immediately? Or it took some time to adjust?

                ravipra norandmaps nokaslr - disable address randomization which is a security feature
                audit=0 - disable kernel auditing
                cgroups_disable=memory - disable cgroups for the memory subsystem (something like a quota system for memory used by the processes)

                Why these though?

                  Could we make a list with good (ergonomic) LCD's, internal or external? My laptop screen has issues, and I cannot find a good alternative, I've tried 2 newer models, they all give headaches.

                    Alyosha2001 The problem is we don't yet know for sure what the issue is, and there is no universally safe panel because it's likely not the panel hardware that is the root problem. I tried a dozen different panels of different specs in a Thinkpad, and tried every new model of every brand I could find in a shop. I have seen a handful of people say the older Dell CCFL dekstop panels of various models are good for them, but I have also seen one or two people specifically mention those same panels causing problems.

                    The one exception in my opinion would be if you have a severe problem with PWM and have confirmed this in testing by getting relief when using a display without it regardless of what computer/gpu/os is driving that display. In that case LG and AUO internal laptop panels usually are PWM free (didn't help me at all and strained as much as brands with PWM) and for desktop monitors you'd just have to find the specific panel inside it and research it.

                      Alyosha2001 My laptop screen has issues, and I cannot find a good alternative, I've tried 2 newer models, they all give headaches.

                      I've been looking for the same thing too - there seems to be no winner across newer devices, maybe some PWM-free TN screen with very cheap graphic card, but it means sticking with Celeron / mobile CPUs. If that's enough for your needs, I'd try to find something in this range. Otherwise it's hit or miss where hit usually means medium strain and miss means headache or severe pain in the eyes.

                      • Gurm replied to this.

                          andc Laptops are rough. You need bottom-of-the-barrel integrated graphics and a known-good OS. And even then it can be hit or miss.

                          • hpst replied to this.

                              Gurm Could you try @ravipra 's Grub config edit above and see if that helps your strain? I'd like to see more examples of this being tested since I can only do it on one device.

                                If I used Linux, I would.

                                • hpst replied to this.

                                  I have a very good IPS panel and I recommend it, by issues I meant it has some functioning issues. The problem with it is that I cannot find it anywhere for sale, because it is not manufacturing anymore. I have tries two of it's succesors from same AUO line, but couldn't use them because of headaches.
                                  I understand that such a list would be very subjective, as long as there seem to be many other factors that contribute to a ergonomic usage, such as angles, colors, contrast, gamma, besides PWM and dithering. I am on Windows and I use Intel Ditherig

                                  • hpst replied to this.

                                    I am using AUO B156HAN01.1and it is good for me. But i've also tried B156HAN01.2 and B156HAN06.1, and, after couple of hours, gave up. The difference in image is also noticeable; even if on paper they are the same, it looks like the newer models regressed

                                    • hpst replied to this.
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