[esolyt]

While it is true that our eyes' horizontal field of view is close to 180 degrees, we can't really "see" that much at once, especially if we are talking about reading.

Watching and reading are inherently different processes.

While reading, you will actually be focused to a very limited area at once. You will constantly move your eyes as you keep reading the text, regardless of how wide the screen is. A longer line requires more eye movement to reach the end of the line and makes it easier to lose track of which line you were at.

While watching, you don't have to make out every little detail in every single frame, so it is a good idea to make the aspect ratio of movies more like the way we see real life.

In summary, a widescreen movie is able to better utilize our "wide eyes", whereas wide text not only fails to better utilize them, but it actually makes text harder to read.

[taligent]

You might have to move your eyes left/right to read.

But it sure beats having to move your head.