AGI Is this a first case of an update of an update that solves an eyestrain issue, and hence there is HOPE?
Can't say for sure. Probably not. I tested a lot of settings/OS/hardware at that time and my eyes were slightly strained all the time. It was just a "first impression" post and I mainly used Linux since then. In the meantime the PC died and I can't currently test it anymore. In the future I try to be very sure at first before asking such questions.
The original Firefox 57 eye strain has been proven over and over again. A downgrade to 56 totally fixed the eye strain.
The first case that took back a very serious eye strain issue for me was, on my iPad 4, the final iOS 7 update. They silently took back whatever they'd changed before that made the whole OS unusable. Some users in the Apple eye strain thread wrote about it. The bad thing is, Apple put the problem back into the iOS 8 beta. So I learned my lesson to stay away from devices that are not downgradable.