This is just amazing how this does not get resolved. For me it has been very clear what the problem is. Until about 2015 it was only PWM. E.g. I have the Surface Pro 2 and still to this day, I'm fully able to use it without any problems if the brightness is 100%, when there is no PWM. If I set it to lower (if I remember correctly, below 70 %), the eye strain begins immediately and it is confirmed by any other person, as my eyes will get bloodshot in 30 minutes. I've used it now close to 5 years and this scenario is an indisputable fact, tested dozens of times.
Now with modern laptops, really several of them, new Surface Pro's, Surface Laptop, HP Folio, HP Envy, Lenovo X1 etc. which have been confirmed to not have any PWM by Notebookcheck.net I still get eye strain. Not as bad as with PWM, but still so that I'm not able to use these at work the full day. I mean, temporarily I can, but I will have irritated eyes in the evening and if this goes on for days, the level or irritation will be so bad that I cannot cope with it. It also hinders me professionally when I have constantly bloodshot eyes. So it is quite clear that these new laptops have something that causes the eyestrain, other than PWM. Temporal Dithering? I don't know since I've not been able to confirm by removing the temporal dithering.
I can use these laptops by connecting them via USB to external displays that do not have PWM.
It is really infuriating that Intel denies the problem as there are so many of us.
I do understand that what makes it difficult, is that many of us do not have so specific scenario. Some don't seem to be affected by PWM, but are affected by what could be Temporal Dithering. Some seem to have problems with fonts or gray colour. Then quite many report all kinds of other health issues, which is making it even more confusing for a person who does not have this issue.
I was talking to an eye doctor - she didn't admit to have seen a case like mine ever before (like many other eye doctors claim), but she did say that I have dry eyes and that dry eyes were previously only a problem of menopausal women. Now she is seeing even 16 year olds with dry eyes. Not isn't that telling something? Of course one could claim that there is some other factor that is causing 16 year olds to have dry eyes, but I really think that the increased usage of devices that have some sort of flickering and the increase of LED lightning has caused this.
And just a remark - I don't have dry eyes if I use only displays that do not have PWM and (Temporal dithering?). I have zero problems with my eyes or eyesight if I only use displays that don't irritate my eyes and there still are many of those displays.
This is so clear and easy to understand, but those who do not have this issue are in complete denial.