You can tell when you read old books that people used to have longer attention spans, and there was nary a screen to read from. Many of the paragraphs are very long, to the point where many pages look like walls of text.
Reading something displayed on a screen is very different from reading something printed on paper. A screen makes white by emitting a full spectrum of light, and a lot of it. If you’re like me and look at a screen all day, you know all too well what chronic eye strain feels like.