jasonpicard I lugged up an old known-good CRT monitor out of my basement about 3 years ago and threw it on my new PC to see what would happen. I did not get the ache-behind-the-eyeballs and sharp headache that I get within minutes of using an LED, but I did get the normal eye strain that I seem to get using any device within an arms-length distance for too long of a stretch of time.
I believe I was also able to perceive the flicker from the monitor out of the corner of my eye quite easily, and maybe even at 75 or 85 Hz or whatever the highest setting was that the monitor could display. I used this monitor a lot playing CounterStrike as a kid/teen, so I know it's good. The only other inconsistency though was that I was using my new PC tower instead of the old one I used to game with this CRT on.
I guess that would be a true test: if you were able to find an old computer and CRT monitor paired together that you were still holding onto that you know never gave you problems in "the good old days"...