[NackerHughes]

A screen is not a piece of paper. Computers adopted white backgrounds with black text, when the technology became available, to imitate the paper and documents that people were most familiar with. But looking at a white screen for prolonged periods of time is like staring directly at a light bulb.

White text on a black background in print is indeed harder to read due to the issue of ink bleeding, but on a computer screen it is so much easier on the eyes.