[symptic]

If he changed the background color to a very dark shade of grey rather than straight black, it would lessen the contrast and ease the strain on your eyes. If you're feeling buzziness from reading inverted type, there is also a good chance your screen is at an unhealthy brightness. Great for picking out contrast, but painful on the eyes. One trick my friend taught me was to place a light source off in the distance to the side, to break up the focused source of light from the screen. It cured his computer-induced headaches immediately, along with lowering his brightness.