I went from a 19" flat CRT monitor to a 20.1" LCD (ViewSonic's VP201s). It took my eyes a couple of days to adjust to the new monitor (and took my bank account a bit longer...). But I do think it's clearer and easier on the eyes.

I don't watch movies or TV on this monitor. I don't play games on it, either (I have a PS/2 hooked up to the TV for games). I use this monitor almost exclusively for coding, email, web browsing (which seems to be mostly PM ;->), and the like. Nothing moving fast, and mostly text. I run at 1600x1200 (was a requirement, and severely limited my choices of monitors).

LCD is not going to have the flicker that can be associated with even the non-interlaced CRT monitors. And, no matter how imperceptible, it can tire out your eyes. LCD should be better for that, but I don't think anything can help if you're doing 9-14 hours at a time with them. ;-) You still have to remember the 20-20-20 rule: every 20 minutes, switch your focus to something at least 20 feet away for 20 seconds.

What kept me away for so long as was the lack of resolution (most LCD monitors have a max of 1280x1024 that I noticed). So when I saw this one within an hour of my old monitor dying, I bought it. Twice the price of other LCD monitors, but the resolution is worth it. I still have 8 desktops nearly all full.