Why is it that when I read white text on a black background, I continue seeing it for minutes afterwards, even when I stop looking at the computer screen, but the same thing doesn’t happen when I read black text on a white (or pale) background?
And why do some people continue to torture us by setting up their websites like that??:mad:
And here I like white-on-black because it reduces eyestrain if you’re working at a terminal (or terminal emulator) for long periods.
OK, on to the question. Afterimage is produced when you overstrain the cells on the retina that percieve light to the point that they keep sending impulses down the optic nerve after the stimulus is gone. Of course, the effect is greatest when there is great contrast in what you were looking at, especially in brightness. So with black-on-white, you are looking at an image that is mostly of the same intensity with some little black spots. With white-on-black, you’re looking at an image that’s mostly black with little points of brightness that overstimulate your little rods and cones on the back of your eyeball. Solution? Take breaks. Look out a window. Pick up a copy of Playboy/girl and … uh … ‘read’ that every so often. 
Another solution is to choose different colors and tell your browser to always use your colors, not the ones the web site says use.
I know you used to could do that with Netscape. Not sure about IE.
Wow, thanks guys.
Short thread!