Maxx well yeah, I'm pretty adamant it isn't because I've already gone through this option. The mentioned ThinkPAD is a pretty old one, and from what I got by googling, it doesn't use PWM. And it still caused severe eye strain. As for the temporary dihtering in high color reproduction screens, it didn't have high color reproduction at all. It should have an even lower sRGB percentage (50ish %) than my Dell (88%). Plus, my BenQ monitor has 100% sRGB coverage and 99% AdobeRGB coverage which is basically as high as it can get, and it doesn't strain the eyes at all (I mean, it is built with that purpose, so that might be the reason, but still, nothing really fits with flickering being the problem).
Also, from what the specs say, HTC 10 has a pretty low refresh rate (60Hz-90Hz), just as my HTC620. So again, this shouldn't be the issue.
And it's definitely not me not being able to get around that fact (because that would be a more logical problem/solution if you ask me than e.g. color reproduction, as some people mentioned changing the ICC profile helped them). But it just doesn't fit considering everything mentioned.
And as you said, it's a problem for most people, but not all. I know a lot of people who have eye pain from flickering. They can't stand waiting in hospitals for example, or working in offices that don't meet the required light standard (meaning they don't use flickering lights, and the color temperature has to be just right), and most hospitals in our area don't meet the standard. And it causes them eye pain, but I don't have a problem with those. So again, it just doesn't seem to be the problem in my case. Not that those lights are super comfortable (but then, the only comfortable light source for me is the sun), but I've never had a problem, nor do I have it now (and I've been to places with flickering lights several times after this eye strain problem started occuring).
I don't want to switch to another phone manufacturer for a reason (I just didn't have good experience with the performance and durability of any phone other than HTC [Nokia 3310 not included, lol], so switching to another would just be a waste of money and a source of frustration). But I might go to a store to try out the Motorola you mention just to see if it causes any eye pain.