@AshX
What an informative and detailed description of the dithering issues, thank you so much!
A. You really have my sympathies. A tech issue like this can literally be life altering (in a negative way) and I don't think it's fully appreciated by anyone not going through it, or something like it.
B. You mentioned OLEDs can possibly mitigate this due to being closer to 10 bit. I wonder if that's why this isn't bothering me, and/or why I find it some comfortable on my eyes with my OLED. I also run a HUGE OLED (65") many feet away, and for a while now.
C. Were older Mac devices and screens/OSes better in this regard?
D. I hope you can find something that works. Is this not an issue as much on other OS options?
A. Thank you. To say it has completely derailed my career in the last 16 months would be an understatement. I did not have an issue with screens or lighting until I got COVID in 2022. It wasn’t until I got reinfected in 2024 that issues became extreme.
B. There are a lot of theories as to why OLED might be better. The problem I see with discussions about screen sensitivity is often it’s framed as if the issues such as PWM or dithering are mutually exclusive. They’re not.
I prefer to focus on flicker as a whole, specifically frequency and modulation depth. For example, I can use my OLED iPhone 13 from 2021 on iOS 15 all day with minimal issues. But when I tested it against every iPhone 13 in the Apple Store that was released in 2023 side by side, I could not use any of them. So it was likely a combination of the new panels for that model and iOS 16/17.
As to why your OLED is tolerable, it is likely because it is more likely to be 10-bit. It’s also likely that because OLED response times are very fast in most cases, you’re not going to get smearing and artifacts like you would on say the MiniLED MacBook Pros which have worse response times than the older LCD Retina Macs. And because iPhones are OLED, it’s probably fair to assume they will be dithering less often than say an iPhone 11, which is 8-bit and will need to use way more tricks to render the colors and graphics on iOS 18 or 26.
C. Once MacOS went 10-bit (I believe this happened a few OS’s before Big Sur, but I believe Big Sur was when the design teams for iOS, iPadOS, and MacOS were unified. The design language is very similar now) it definitely got worse.
Older Intel Macs were largely dependent on a few variables:
- GPU (Intel or AMD)
- Processor
- Panel type like TN or IPS, plus Apple specific designs (Retina, non-Retina, Liquid Retina, etc)
- Backlight (CCFL, edgelit LED, etc)
- TCON (how often the panel will use FRC to dither)
For example, my 2019 iMac 21.5-in 4K Retina could toggle between 8-bit and 10-bit (millions and billions of colors) using SwitchResX. It helped take the brunt off the dithering on that machine and let me use it after my first COVID infection. But some flickering still remained, despite it being on Mojave.
Some have been able to disable it via terminal commands, but because of the variance in models, processors, OS, and so on its hit or miss. Stillcolor disables GPU dithering but not TCON FRC which is controlled by firmware not accessible via user space. So all the Apple Silicon Macs still dither even if you disable GPU dithering.
D. I haven’t used Windows since I was a kid. Windows 11 is apparently very problematic. The entire industry is shifting to P3 color, so more and more devices are dithering. Every laptop I know to exist is 8-bit + FRC, not true 10-bit. I know people swore by certain instances of Windows 10.
This is the problem. Dithering can be enabled via an OS update. Apps like Photoshop can force dithering to be enabled and even override Stillcolor.
What I think needs to happen is users need to be given control. There should be an Accessibility option to disable it if it affects your health. I don’t think that would take much, after all Stillcolor just alters one command: enableDither=no. So the talk of Apple needing time to implement it just isn’t true. They could equally send a command to the panel’s TCON to disable FRC. At the very least this, plus offering PWM free, flicker free devices, would give people who have neurological and visual disabilities - as well as those who are health conscious or would prefer not to look at the equivalent of a strobe light all day - an option.
That’s all I’ve been asking for, and I’ve been speaking to journalists about this. Myself and many other long COVID “long haulers” plus others with health conditions have been affected by this for years. It’s not the 1960s - you need a phone and a computer to function in careers and society. They’re not a luxury. My banking apps aren’t even working on iOS 15 anymore. So my choice is update to iOS 26 and lose access to the only screen I can even look at. It’s not a choice at all.
We will look back at this in 10 years and go what were we thinking regarding flickering LEDs and screens. I may be one of the most severely affected individuals, but as a top NYC ophthalmologist told me, everyone is affected, they just dismiss it as blue light or screen time. It’s not.