For the record, i run a bad-ass CRT at 85hz which is the perfect level for me, i never get tired eyes so i know it's working - but with LCD screens it can also be the sharpness, contrary to what the marketing claims, sharper image = more stress/fatigue
But hz and framerate are different things, i don't mind lowish framerates in the 30's but i could never play at a 60hz screen without making pauses every hour... no matter the framerate ;p