I ran into this by accident when playing around with styles for my site awhile back. Turns out this specific optical illusion is more pronounced for near-sighted individuals when wearing glasses. An oddly specific super-power.

Here's an example:

If you don't see the illusion, the red parts seemingly jump out of the screen, and the blue parts are sunken further back. If you search around on the internet, there are tons of cool examples that people have made running with this technique.