I wonder if there anyone besides @KM who can use somewhat modern phone with modern android? I went all the way down to 2014 phones and still get headaches and eye strain. My almost dead Lumia is the only "window" to this world. I was trying to find used Meizu M1 METAL, which does not cause me eye strain, but there are none for sale, it was unpopular.
Also I started to talk with people about this eye issue and what's interesting, iPhone owners say that they eyes get tired very fast in comparison to other phones. Some people (including my mom) say that she gets a blurry vision for a hour or two after using iPHone for longer periods. For me the iPHone was the worst from all other phones, so I think that it damages vision very fast for everyone, just that we are very sensitive to this and cannot look at those screens at all. Maybe it is a good thing for us...