I'm a programmer, and I was having alot of trouble a sitting behind a computer for long periods of time. After a few hours my eyes hurt like hell. I asked my eye doctor, and he recommended reading glasses, which helped to some extent. Then a fellow worker, who also suffered from eye strain, recommended full spectrum light bulbs. These bulbs have a EM spectrum similair to real sunlight (in contrast to incandecent and flourescent lighting). Once I started using them, all eye strain was gone. I can sit behind a computer all day now without any problems. In addition, my near sightedness, which was getting progressively worse, has stablized. I've been using the game prescription for years.

I have recommended using these bulbs to others who work with thier eyes up close, and they have reported beneficial results as well.

As to why this works, I don't know for sure, but my guess is that our eyes developed for use in real sunlight, and the bad spectrums of artificual light wreaks havoc with our eyes in some way.