I’ve used Apple computers extensively for twenty years. In 2019 I purchased a 27” iMac Pro. From the moment I booted it up and saw the white apple over the black background, looking at the screen gave me a headache and eye strain/fatigue IMMEDIATELY...NOT AFTER some period of time working on the computer. If I look to my left or right (away from the monitor) the headache and eye strain almost immediately faded. I've adjusted the brightness, I've tried 3rd party apps like "f.lux", “Shady" and SwitchResX. I adjusted the resolution down to 2048 x 1152, I've tried sunglasses as well as computer glasses to further adjust color, I've used the "Night Shift" feature and I've spoken with Apple Care. I've seen my ophthalmologist and he has no ideas either. I'm looking down at the monitor and am approximately 29" away from it because of my desk size and chair position. The headache and eye strain is definitely at peak pain when the screen has mostly white on it, like most any internet page (like this one). Color temperature adjustments provide some feeling of relief but in a very minor way. Inverting the colors makes my head feel even worse.
For background, I'm a technology trainer who spends all day, every day staring at all manner of PC, Mac and television monitors while teaching staff software. Been doing this for 15 years. Never experienced this problem before. The only other experience anywhere close to this was when I purchased a 50" LCD about 8 years ago. It seemed fine in the store but when I got it into the home it immediately gave me headaches and severe eye strain. I exchanged it for a PLASMA tv and have had no problems since. I suspect the issue there was a refresh rate that my body did not like. My understanding is that the refresh rate is not adjustable on the iMac Pro display, even if that's the issue (and I can't be sure it is).
Now here is the kicker. After a year of not using the iMac Pro at all, working only from my 15” 2019 Mac Brook Pro, I again fooled around with all these third party apps and terminal commands on the iMac and actually hit upon something that instantly made the problem go away. But I don’t know what it was that I did to achieve this. I counted my blessings and just went back to work on the iMac Pro.
For the past year and a half working from home during Covid, my employer gave us the option of adding a second monitor to our home setup to make work more comfortable. I ordered one but avoided hooking it up for most of that time on fear that the moment I connected the external monitor to the iMac, it would change the screen resolution on the internal display and bring back the pain.
Recently I thought it would be a good idea to note all the specific settings I currently had for the iMac Pro so that if the problem re-emerged I could attempt to restore it to its current configuration. I wanted to see the precise resolution I was current set to. In order to do this on the Mac I needed to go into the System Preferences > Displays and hold the OPTION key while clicking the SCALED ratio button. The moment I did that, something changed and the pain returned. There wasn’t a radical change in the desktop appearance but I could see that the fonts seems to get a little crisper and the colors might have gotten a little more vibrant. The size of the fonts and desktop did not change.
And now I’m back to the original problem. I used the opportunity to hook up the second monitor, which is an HP E273. While that’s not a Retina monitor, looking at it also hurts my eyes a bit. I suspect because whatever the iMac is doing, it’s also doing to the HP display.
This is frustrating because I know it’s fixable, but I don’t know what I did to eliminate the issue the first time.
Any thoughts or recommendations would be appreciated.