I'm in the process of borrowing a Window laptop so I can see if I have similar issues with it's screen and my monitors. I'm guessing not as I have had WIndows machines at the office for years with no problem, but we'll see.
In the meantime, I wanted to try and refocus on the specifics of my iMac Pro issue. While it's clear that I am one of the unfortunate who a sensitivity to some specific type of computer display phenomenon, I also know that I was able to use these machines with the same existing software and operating system without any issue at all for years until a week or so ago. My goal is to revert the machines back to that state rather than go down a rabbit hole of eye diagnostics. I've worked in broadcasting and computer training my entire career and have only experienced these eye strain issues with these two machines, which until about a week ago, I had no issues with.
To review, I originally had a severe eye strain issue with my 2017 iMac Pro. Using some technique that I can't remember (possibly SwitchResX, terminal commands, memory resets), I succeeded in eliminating the issue entirely. But when I recently opened the System Preferences on the iMac Pro, went to the Display tab, held the OPTION key and clicked the Scaled radio button to reveal the current screen resolution setting, I instantly noticed three things: #1 the colors got more vibrant #2 everything got slightly brighter #3 the text and icons got crisper and more defined. The size of the text and icons did not change. It was at this point that the eye strain instantly returned. Also, when I hook up external non-Retina monitors to the machine I still have the eye strain. I'm trying to figure out what these specific clues tell me about where the problem probably lies and how to get it back to the way it was. What adjustments can I make that will make the colors less vibrant and the text less crisp? So far, flipping through the various color profiles hasn't done it and all attempts to turn off dithering/font smoothing using either terminal commands or third party software haven't seemed to change anything. With respect to dithering/font smoothing, It's literally like they aren't doing anything at all…I see no difference visually, let alone eliminating the eye strain issue. You'd think that even if it didn't resolve the eye strain issue, I should see a visual difference when attempting to turn off smoothing/dithering. I've also used SwitchResX to change from Billions to Millions of colors and to choose only non-HiDPI resolutions.
Logically, when I held OPTION and hit the SCALED radio button, the purpose of that action is to show you all the possible resolutions that the computer can offer. When you don't hold OPTION and just hit SCALED, it just shows you a few options. So when I executed that keyboard move, i'm guessing that it changed whatever manual overides I made to fix the problem, and forced the screen back to only those resolution configurations that are pre-established in the Mac OSX, mostly likely to the one that most closely mirrored the pre-existing non-eye strain configuration I had, since the size of the text and icons did not change, just the crispness and colors, both of which got more intense.
One more clue. When I Screen Share my iMac Pro to my Plasma HDTV via Apple TV via HDMI, I still feel the eye strain on the HDTV showing the iMac Pro Desktop. Everything is slightly less crisp since it's a TV and not a computer monitor, and the colors may also be a little less vibrant, but the problem persists.
So any ideas on what to try to put it but it back the way it was?