Whether you’re a night owl like me or just occasionally stay up late to work on your computer, you might be interested in a piece of software called f.lux. The software can alter the color temperature of the computer display to match your indoor lighting and in doing so hopefully take some strain off your eyes during work. This is not purely meant as a cosmetic change but also intended to aid sleeping after working at the bright screen in the wee hours.
One caveat is though, that the software’s color distortion is no good for graphic design work.

Versions of f.lux for Mac OS X, Windows and Linux can be downloaded from http://www.stereopsis.com/flux/.