Hey José,
I’m a Brazilian living in São Paulo, and I first noticed I had issues with LED screens around 2019 when Apple released the 16" MacBook Pro. It was the first Apple device that gave me trouble—migraines, brain fog, you name it.
For my own devices, I’m using an iPhone 12 Pro with iOS 17.7. I updated to iOS 18 a few weeks ago, but I’m pretty sure they added temporal dithering in the new version because I started feeling off just a few minutes after the update. I had to roll back to iOS 17.7, and things went back to normal.
I’m also using a MacBook Pro 15" (2019), which is one of the last models with Intel CPUs. I can’t handle any MBP released after that (including the 16" Intel model and anything with Apple Silicon). I’m running macOS Sonoma 14.7 because they enabled temporal dithering on macOS 15 too, so I had to downgrade, just like with iOS.
I’m pretty sure it’s a mix of both hardware and software causing the issues. PWM doesn’t seem to be the main problem since my iPhone 12 Pro uses it at around 250 Hz and I don’t feel anything. Temporal dithering seems to be the main culprit, as I mentioned with the latest macOS and iOS updates. I’ve also tried several Android phones, but all the newer models with AMOLED or IPS screens give me trouble.
It’s really hard to troubleshoot since, like I said, it’s a mix of PWM, temporal dithering, and the screen panel itself (probably the backlight). So, you never know which one is actually causing the problem.