After doing a pretty exhaustive search and trying every possible solution I've found on this lovely forum (no joke), my screen brightness is stuck on max. I'm running Ubuntu 12.04. Seems to be a common problem, but it's a little frustrating that nothing seems to work.
Going into system settings, it appears to be set on minimum (yet it hurts my eyes even in a brightly-lit room), and sliding it back and forth doesn't change anything.
Alternatively, is there any software that will dim the brightness to a more tolerable level, in case I continue to run into brick walls?