So after reading all responses I think we can all agree there are no solid experiences that would lean towards Mac OS as primary cause of eye strain, although it plays a part by interfacing with hardware. But from more practical terms, attemting to solve software problems, could lead to work without tangible results on wrong hardware. Apple devices may not nescesarily fall into this category due to close software and hardware integration, but then closed nature of software is probably an issue. The question is - are there aspects of software that control parameters of hardware directly linked to eye strain regardless if those are accessible now or will be made accessible in the future? (I am excluding obvious UI based elements like font smoothing etc with the assumption that there is something more harsh as some flicker/modulation tests have shown in other posts)

    Donux

    Direct interaction with the equipment is hidden in modules whose source code is not openly available. This creates a problem and leads us to the need for reverse engineering (decompiling and studying the assembly code of these modules). As I understand it, Apple explicitly prohibits this in the EULA: https://developer.apple.com/forums/thread/687343.

    But even if it is possible to resolve the legality issues, without the source code, this is an incredibly labor-intensive task.

    • JTL replied to this.

        WhisperingWind Direct interaction with the equipment is hidden in modules whose source code is not openly available. This creates a problem and leads us to the need for reverse engineering (decompiling and studying the assembly code of these modules). As I understand it, Apple explicitly prohibits this in the EULA: https://developer.apple.com/forums/thread/687343.

        In some places, reverse engineering legitimately obtained products for investigation and correction of issues is not illegal.

        I think a more pressing concern is the possibility of complexity with isolating and investigating which component is potentially responsible for the "cause and effect" of a particular issue.

          10 days later

          WhisperingWind Does anyone have the kext from Amulet that disables dithering for AMD graphics cards on Mac?

          It was linked on this forum a few times, but the links I found appear to be expired. The filename was AHKinject_SCN078.dmg. This post was a summary of all the info I could find about disabling dithering on Intel macOS, and it had a few links that might point you in the right direction. If you can figure out my email address, you can message me privately for more info.

          Note that I could not get ahkinject.kext to work for me consistently, as it would only work for about 30 seconds before reverting to dithering (established via capture card). Someone also apparently had to patch the kernel extension for newer macOS versions, but I'm not sure whether the patched version is publicly available.

          simplex Old capacitors can pass voltage pulsation.

          Also, if monitor is old, blue peak of LED is extremly big (the main issue of this phenomen, is LED coating got cracks due to temperatures, and blue spectrum starts to emit directly in your eye/retina). I stoped using my "safe" old laptop without dithering but having increased blue peak, and eyes become better in terms of sensitivity. I also replaced all LED room lamps (all PWM free, sunlike or big yellow 2800k peak types) into halogens / incandescent

          simplex Using old/used phones is not good idea:
          ...

          1. The screen is worn out, the blue peak becomes higher than at the beginning, the screen becomes "cold" in shade - no solution, because it is impossible to find a new screen. And it is unknown from what LEDs / spectral the screen replicas are made. And it is unknown in which replica there will be FRC/dithering and in which - not

          I believe you established this via empirical spectrometer readings, so I tentatively agree that this happens but I have a few thoughts/discussion points:

          1. Is there any more data available on how widespread this kind of LED backlight degradation is? Were these specifically computer monitors that were tested, or smartphone screens as well?
          2. I presume you would draw a distinction between old (as in age) versus high usage hours? So someone who can find an older panel in new condition or with low hours could still reap the benefits.
          3. What about blue light filtering glasses to mitigate the effect of higher blue light emission on older panels?
          4. I have found that some heavily-worn screens do hurt my eyes; however, my impression was not that they turned blue, but rather yellow/brown. I attributed this discoloration to degradation of the film layers intended to transmit/diffuse the light, rather than degradation of the LEDs themselves, but I am now reconsidering this. I do find older displays to be bluer in general versus modern screens, but I attributed that to modern screens getting redder (especially wide-gamut and KSF phosphor panels), rather than the other way around.
          5. For those who can tolerate CCFL backlights, I wonder if refurbishing CCFL screens is a viable option, since replacement CCFL tubes still seem readily available. As far as refurbishing LED-backlit screens, I've seen at least one video of a repair shop replacing individual LEDs for a screen backlight, but the technology is generally more miniature so I would be skeptical of whether this is generally practical for LED-backlit screens.

                A program certainly is able to introduce (additional) dithering.

                The new Chrome browsers on macOS

                The new Transmission client.

                And so on

                  sdkjbfakgljbafkjb

                  Which specific app versions and operating systems are causing issues? I will include them in the list for analysis.

                  Did you use StillColor or BetterDisplay to disable dithering?

                  What monitor are you using (8-bit, 6-bit+FRC, etc)?

                  What Mac do you have?

                      WhisperingWind

                      On macOS Catalina, which has no significant dithering in the OS (I know of)

                      However the newer Chromes (>= 120) and Transmission 4.0 on it really annoy me, very hard to look at. Chrome specifically has this weird "sleek" look where everything is very sharp and blacks are very black.

                      But it's fine I just use older versions of them

                          sdkjbfakgljbafkjb

                          On macOS Catalina

                          Sorry, I can't perform the analysis on macOS Catalina because I have only an Apple Silicon Mac.

                          On Apple Silicon running Sonoma 14.1.2 and Chrome 133, any flickering is absent (I use StillColor). Perhaps the browser's rendering engine has color settings that make the rendering result more contrasting. I have noticed that a high-contrast and sharp image strains my eyes, and perhaps the same is true in this case

                              WhisperingWind

                              Yeah it's fine I just use older versions.

                              But basically, it seems even single windows are able to introduce temporal dithering on macOS (even when otherwise there is none) 😛

                                Adding this here because I'm positive a Mac OS version difference causes it on identical hardware. I'm still leaning toward "temporal dithering" being the cause and I'm locked at Mojave on a 2013 MBP. Updating to Catalina caused in instantly so I reverted. When that laptop died because the keyboard could no longer be repaired I bought the same hardware model which had been updated to a newer OS and caused strain issues. I used a factory reset and time machine backup to boot into Mojave and it was fine again. On this machine for my eyes Catalina OS and newer were the culprit.

                                Recently I accidentally updated Brave browser and somehow even on this OS/Hardware the browser itself seems to have introduced dithering (newer Chromium?). Others have reported it being related to the hardware acceleration setting but there might be a bug preventing it from stoping when I turn it off. Firefox is fine so I've switched over.

                                It's a software/driver issue or a complex web, not simple hardware. Friends have suggested simply using an older monitor but you can plug in a 1920x1080 monitor from 2010 into a new mac and it will be nauseating. It's a software/driver thing. I'm positive of that.

                                Similarly, Windows/Linux seem to be copying Mac- or is it the GPU companies? Unsure but I'll get the same effect on an increasing number of non Mac computers.

                                I hope to try higher end monitors like BenQ and one of the nano-coated screens from Apple, as I've heard some have success with them.

                                  amusesmile

                                  This seems like proof that applications can introduce dithering so long as they’re running? Was this limited to the browser window itself?

                                  Absolutely wild that this is even a possibility, especially on systems that are allegedly disabling dithering on a system level (Stillcolor, SwitchResX, Betterdisplay).

                                      AshX Not to muddy the waters, I just want to mention that this Brave browser thing on the old computer causes maybe 10% of the issues compared to anything on my Silicon iMac, which is instant nausea even with Stillcolor. No idea what's up if that's actually working. I could deal with Brave Mojave if I had to.

                                          amusesmile

                                          issues compared to anything on my Silicon iMac

                                          The issue here might lie in the display itself, rather than macOS or the GPU. The display of your iMac is wide gamut. Such displays often use technologies that can strain the eyes significantly on their own, even in the absence of PWM and dithering. Moreover, Apple does not disclose the exact specifications of their displays, and it’s possible that some colors are rendered by the display using temporal dithering (FRC).

                                              WhisperingWind Just to mention though, on this old computer from 2013, when I update to Catalina it feels nearly 1:1 to the modern iMac despite very different display hardware. This indicates to me that it's more of a "how the hardware is being controlled" rather than "what are the physical limitations of the hardware" problem. Maybe the terminology hardware/software/driver can add their own difficulties.

                                                WhisperingWind The color Gamut issue is interesting though and I'd like to understand more about how it works. I've done tests like creating interfaces or web pages with only two colors. It's my understanding that we still get the nauseating effects because on the edges of rendered text there's dithering applied to smooth black to white or one color to another. In some sense there's not actually a way to control individual pixel colors- everything is smoothed in transitions and flickers to have more color gradient that what is possible on the display.

                                                    amusesmile

                                                    The color Gamut issue is interesting though and I'd like to understand more about how it works.

                                                    When using KSF phosphor (which can be applied to LED backlights in wide gamut displays), there is a slightly reddish tint mixed into all colors. This is because KSF phosphor emits light in the red region of the spectrum, which enhances the saturation of red colors. However, this can also lead to changes in the spectral distribution of emitted light, affecting the overall perception of colors. Some people may be more sensitive to changes in the light spectrum, especially if there is a strong peak in the red region. For me, this creates a sensation of a "reddish tint" and discomfort during prolonged use of such displays.

                                                      amusesmile I’ve had a similar experience, with browsers specifically. I have a 2017 MacBook Pro 13 without Touch Bar. If I use it on Catalina with the built in Safari version 13 it’s fine. If I update Safari past that I get eye strain but in Safari only. I noticed this phenomenon starting to occur in other browsers around the same time MacOS Big Sur came out. First Safari (versions 14+), then Chrome (unclear which versions), then Firefox after 122/ESR 115.7. The current versions pretty much all cause eye strain now for me on MacOS despite the underlying OS UI and other included apps still being ok with minor settings tweaks. I think it corresponds with the increased adoption of newer web standards for color management/hdr/wide color starting around 2020/2021 but I don’t know for sure.

                                                      I currently have Mac OS Ventura installed on it and I don’t have an up to date browser that is 100% ok eye strain wise. But other stuff besides the browser is more or less ok.

                                                        amusesmile Updating to Catalina caused in instantly so I reverted. When that laptop died because the keyboard could no longer be repaired I bought the same hardware model which had been updated to a newer OS and caused strain issues. I used a factory reset and time machine backup to boot into Mojave and it was fine again. On this machine for my eyes Catalina OS and newer were the culprit.

                                                        This mirrors my own experiences. I have a Mojave Macbook Pro 2103 in front of me.

                                                          dev