• Abstract

  • Anti-aliased fonts can damage eyesight - writeup

JTL
This naming is confusing indeed: 8 bits per channel may equal 24 bits per 3 RGB channels, as well as 32 bits per RGB + transparency. I initially thought that 24 and 32 bit screens are different
E: I've just checked the link you provided - it says the same thing 😃

  • JTL likes this.

    24 vs. 32 bit screens is ALSO misleading - most screens are in fact 18-bit and simulate 24-bit. There are a VERY FEW 30-bit screens.

    • JTL replied to this.

      Gurm 30-bit = 10-bit in marketing speak iirc.

      • Gurm replied to this.

          JTL Correct. Which, as I said, there are like 5 of. It's frustrating, but most displays are 6/24 bit. This is why every device flickers. 😉

            oh looks it's not the bit depth that is my second problem but DPI!! Accidentally noticed that under SwitchResX there are HiDPI and same resolution as regular ones, as soon I picked non HiDPI my Mac discomfort lowered (both on the Retina display and the External one).

            Besides not being able to tolerate "smooth fonts" looks I can't tolerate DPI > 1x
            https://wiki.archlinux.org/index.php/HiDPI#Chromium_.2F_Google_Chrome

            Here is output of chrome://gpu/ output from my comfortable chromebook
            Display(s) Information
            Info Display[12528934998507520] bounds=[0,0 1241x698], workarea=[0,0 1241x650], scale=1.1, internal.
            Color space information {primaries:INVALID, transfer:INVALID, matrix:INVALID, range:INVALID}
            Bits per color component 8
            Bits per pixel 24
            Info Display[13702326689085187] bounds=[1241,0 1600x900], workarea=[1241,0 1600x852], scale=1, external.
            Color space information {primaries_d50_referred: [[0.6663, 0.3285], [0.3202, 0.6144], [0.1480, 0.0513]], transfer:0.0000x + 0.0000 if x < 0.0000 else (1.0000x + 0.0000)**2.2000 + 0.0000, matrix:RGB, range:FULL}
            Bits per color component 8
            Bits per pixel 24

            At this point I use same external monitors, same font, no smoothing, DPI scale 1 and the Mac still gives me slight discomfort, it's has slight blurness, however I would say 95+% my situation has been improved 😃

            Looks if iPhone X feels worse than iPhone 8 then it's the DPI, DOES SIZE MATTER? section on this link
            https://www.zdnet.com/article/iphone-x-or-iphone-8-price-size-camera-all-factor-in-your-buying-decision/
            as it has higher scale.

            • hpst replied to this.

              Im thinking about this and it makes quite a lot of sense. Imagine when some mentioned that older OS on a good comfortable phone was ok and new one wasnt. Maybe the font rendering in that new update changed, the fonts are more blurry and impossible to fix your vision onto, thus the issues.
              Or of course dithering which is still hard to prove and Im not sure why it would change inbetween software updates, but it could of course.
              If every outline of every box, font and image is anti-aliased (blurry), then it would makes sense how we feel "unable to focus" most of the time. Its very simple, easily overlooked and for example on iphones impossible to fix. Supposedly though you can change fonts on jailbroken iphone, would be a good idea to try that.
              Technically also if you have the same OS on an older and newer iphone, the OS still knows which iteration of iphone it is and could therefore still render differently between those two devices.

              daniel_mate

              Is DPI the same as scaling in this context? On KDE neon there is a scaling option and since my panel is 1080 its way too small at 1.0 and I use 1.5 to make things big enough, but I cannot use that laptop due to strain anyway. I also tried leaving scaling at 1.0 and reducing display resolution to 1600x900 but it didn't change the strain. It would be great if simply a set of rendering/scaling/resolution settings could solve this.

                  hpst yes I think I use it in same context
                  When picked same resolution on the Retina, just non HiDPI, the scale changed from 2 to 1 and now both my retina and Air laptops feel same...tho still have discomfort but at least my eyes don't feel like they want to flip instantly (after disabling anti-aliasing too).

                  • hpst replied to this.

                      daniel_mate Do you know Linux? I am trying to figure out how to replicate your results in Linux. If I put scaling to 1 or don't increase DPI in another place the text is too tiny on a 1080 14" screen. There just isn't any way to get a 1080 14" display readable without adjusting SOMETHING to make text and elements larger.

                          hpst I do.

                          I got Red Hat Enterprise wks last week to experiment at work
                          It has NVIDIA Corporation GK107GL [Quadro K420] (rev a1) + Lenovo ThinkVision P27h-10 27 monitor.
                          It had pre-installed the nvidia settings tool
                          As is it came with grayscale auto aliasing.
                          Disabled dithering over it too, but have no clue if it did anything.
                          I use 1600x900, and chrome says scale=1...yeah this resolution is pretty big (huge everything)
                          This setup feels same to me with the Macs (after disabling their default sub-pixel antialiasing on them)

                          This Linux and the Macs give some blur/smooth feel of everything (not just the fonts), where the good Chromebook and Matte TN Mac feel sharp and pixelized (also talking about pictures not just fonts)

                          ...on my to do is to experiment with different live linux CDs on the Macs.

                            2 months later

                            daniel_mate

                            In MacOS Mojave, unless I enable old-style font smoothing, I get a lot of eye strain and migraines. Even if I pick "strong" font smoothing instead, it's just too weak and the text is too faint and spiderey.

                                Ananiujitha I think that is normal. This Mojave "issue" got so many write ups cause almost everybody on non-retina displays is affected. The change is visible for worse quality and I guess even people with good eyes get strain with it after short time. ...but for people with bad eye/s like me that can look for few minutes only the bad quality one is more tolerable than the beautiful smooth one.

                                • AGI likes this.
                                  a year later

                                  Been having the same exact issue on Linux for years. Different GPUs, displays (except for IPS), drivers, playing with fonts and whatnot never solved it for me. Yes, it's an issue which you can only feel, not see. Yes, you can't focus on text or elements for too long, everything feels fuzzy, juddery and makes your eyes wanna roll inside your sockets. This stupid thing has been keeping me off Linux and I don't get it why only a few people are affected by this. It doesn't make any sense. What exactly is missing here, and what is so special about Windows? Whom do we have to address about this? Nvidia, ATI, Xorg or Kernel devs? WHAT do we tell them exactly? These are all 1 million dollar questions. We have a discussion open here as well: https://ledstrain.org/d/785-eyestrain-when-switching-from-windows-to-linux/31

                                  Please, join if you have any solutions or just want to help us expand our "strained" community.

                                  a year later

                                  I think using a bad monitor is the primary reason for damaged eyesight. Pick a better monitor from here

                                  2 years later
                                  dev