To me it seems that something is wrong in combination of specific graphic cards and screens.
It seems that most of the laptops based on m3-7y30 processor are easier for my eyes - they use Intel HD 615 graphics card different to current standard HD 620. Most HD 620-based laptops cause issues in some way.
What's more - for me, there is visible difference between glossy screens using low frequency (below thousands) PWM and these that aren't supposed to do it. I can tell with 80% chance which screen is using PWM by simply looking at the white area on screen turned to 100% brightness (i.e. there's no PWM running). White color on these with PWM is more stable, solid, basically it doesn't have too much of "snowing" effect and looks like easier to look at. Screens that don't use PWM are usually harsh, they're hard to look at, and within minutes I can feel first signs of strain. Something seems to be moving on them, although I look at the plain white color. They act like unstable surface on a micro-level.
This leads me to thought that the issue may not be just dithering to achieve greater color depth, but also something like dithering that's used to dim the display. This instability on white screen is strange as every pixel should be equally lit, and as a full white color - there should be neither dithering, nor PWM on them at all.
Screens that utilise PWM don't have to use some sophisticated tricks to make the screen darker - they basically turn parts of screen on and off - it leads to strain and other issues, but is easy to identify using phone or oscilloscope. The problem is bigger when LED screen doesn't use PWM. To me it seems that pixels on such screen aren't set to be run in sync with each other as it is with PWM (where they have to turn on/off at once), but flicker or alternate colors on individual pixel level (something that could be seen to some extent on my microscope tests in darker shades). As a whole area they have stable brightness, but individual pixels dance all the time. Dithering itself wouldn't probably cause issues on white screen (there's nothing to dither, and it's a max brightness on each pixel / subpixel), but there might be OS/driver/screen built in mechanisms that cause these pixels to change on every color. It's strange, but seems to be a logical thing based on what I've been seeing.
I'd really like to know if any of our ideas is spot on - access to person / article explaining how screens / graphic card algorithms work would be perfect for better understanding of our issues.
As a final word , I think the situation will have to change eventually. Technology is evolving all the time, please recall screens / devices that we used 10 or 20 years ago. Current LED / dithering / PWM ... generation is horrible, but in the end everything will get replaced by something else. Let's hope it will be better 🙂