So, I went from a Sony FW-900 CRT with zero eyestrain from 2004-2009 to a Samsung 2233RZ (first LCD that wasn't total garbage for gaming), still with zero eyestrain. In 2012 I got an Asus VG278H which added a bit of eyestrain, but I figured I was just getting older. In 2014, I got some Gunnar glasses, and this helped enough that it wasn't a big problem anymore (although I'd still get bloodshot eyes after 4 hours)
Later in 2014, I bought an Asus PG278Q (still a TN panel like all the others), and it felt like I was looking into the damn sun. I ran it at zero percent brightness (it's not PWM), turned windows brightness to 35 percent on top of that AND wore anti-blue glasses. It still hurt, and my eyes would still be red after 2 hours per day of use. The monitor was almost as good as the CRT for gaming though, I really liked it.
In 2017 I bought a PG278QR, which had built-in anti-blue settings and was apparently less prone to problems (and I suspected the "insane" brightness might have been a problem with my first-run PG278Q), but even with this AND the anti-blue glasses AND zero percent brightness AND sunglasses on top, it STILL hurt. I also added Philips Hue lighting to my room so I'd have a nice natural lighting tone behind the monitor.
At some point I got a laptop, and the screen also killed my eyes there. This was an IPS panel this time.
That was the straw that broke the camel's back. Both IPS and TN panels hurt my eyes, but only newer ones. I've always been running Nvidia 9 or 10 series hardware in Windows, which means dithering was always disabled. I threw in my old 780TI and made a Windows 7 install, then connected my PG278QR to that - no change.
I decided to sell the PG278QR and buy something totally different - a VA panel (LG 32gk850g). This... has finally solved it. The bags under my eyes are significantly reduced after only a week, and my eyes are very obviously less red (at all). I still wear anti-blue glasses but I don't use the anti-blue modes on the monitor. I can stare at it for 12 hours without discomfort. Gaming is still possible on this monitor, although motion clarity isn't in the same ballpark as the PG278QR. Movies are improved on this one, however.
Just thought I'd post this, in case anyone else is hoarding old CCFL monitors. Try a high-end VA panel!