http://images.devshed.com/dh/stories/Oblivion_Review/oblivion_dungeon.jpg
http://www.gameandplayer.net/images/inset/inset3_08_0115_fcom.jpg
Oblivion nights:
http://img401.imageshack.us/img401/7500/oblivion5wp5.jpg
http://img526.imageshack.us/img526/3337/oblivion16yx6.jpg
Seriously, if you needed torches there, you have a "vision problem". No offenses.
It's more about what is is good for the eyes I think. It's not good for your eyes if things are too dark.
Try using darkness mods for Oblivion and see how it affect your eyes after long plays.
It's like with music. You can't have too loud of too extreme soundtracks all the time, despite how epic and good they might be. That will hurt your ears. It will become more of an annoyance after long plays.
Same thing with too much contrast in a game.