I *think* LCDs will eventually heal themselves. At least I think I've read that somewhere before. CRTs won't.
I remember not being able to play the Telstar game console (a Pong clone) on our color TV. Only on the shitty black and white. I'm SURE that would have burned into a CRT. That's probably why parents freaked out about Atari 2600 and other game consoles burning in too.