hpst I really wish I knew. Drivers are complicated, Intel claims they found NOTHING when they analyzed their drivers from a known good to known bad config. I don't buy that - clearly something is very different and we know roughly when it happened. That might be a place to start. Find a known good and known bad config. The problem is that this is cropping up in so many different ways - drivers for some, chip iterations for others, VBIOS settings for others, and options for another group.
On my phone (HTC One m8, Verizon), updating the "firmware" (not really firmware on an android device) from the version that shipped with Android 5.02 (Lollipop) to the one that supports Android 6 (Marshmallow) was what did it - this isn't really firmware in the traditional sense, but rather it's the low-level drivers for the hardware. Even just puttering around the bootloader screens hurt after that update. Sunspark found that on some versions of the device there was an alternate driver set for the Harman/Kardon equipped models that made his ok to look at. That didn't work for me. But in that case it was CLEARLY the low-level display drivers that broke the device for me. No idea how to disassemble those, but I have both sets. HTC cannot be reached for comment, but there are a ton of hackers out there...
On Macs it is clearly the screen - my 2011 Core i5 Macbook Pro was fine until I sent it to Apple to get the screen assembly replaced. It came back hurting my eyes. Some Macs have "magic" screen/chip combos (early 2013 has a GeForce 6xx and are great, late 2013 has a GeForce 7xx and isn't). Apple not only doesn't care - on their forums their moderators mocked us openly and when we complained about that WE got banned. Apple doesn't give two shits.
On nVidia cards it's the vBIOS - MSI 970's are fine, but other newer versions aren't. 960 and 950, being newer chips, usually aren't. Will nVidia tell us what they changed? Who knows?
On ATI we're pretty sure it's drivers, when we used to be able to turn off dithering it was ok. But that was a while ago, and it was for an older version of the card, so who knows? It could be vBIOS or hardware for them too. AMD is unlikely to listen to us, but I guess we could ask.
Windows 10 introduced compositing. It's ABSOLUTELY the support for composition layers that makes it hurt, since the initial release did not, and all versions right up until they introduced that support didn't. Newest version (1807) is better than previous versions were, I can use it for 15-20 minutes without trouble, but I can use 15xx all day with the same hardware. I submitted a bug report to MS. No response.
On my XBox One, Destiny 1 is fine. Destiny 2 hurts. I got used to whatever they were doing, and could play for an hour without issues, until the latest update from MS/Bungie. Now it hurts again. If I put in Destiny 1 it is fine, no issues at all. Clearly there's some new video mode they are using. Some games use it, most don't. Will Bungie tell us what that is? Probably not.
Where am I going with this? I don't know. I have no idea how to proceed, but we're rapidly approaching a day when I can't work or make a living and it scares me.