The riddle asks: "What has 4 eyes but cannot see?"

Answer: Mississippi

Explanation: "Mississippi" has four letters "i". In the riddle, these "i" are the "eyes". But of course, a word sees nothing. It is just ink on paper. Or bits on a screen.

There are more things with "blind" "eyes". Potatoes have those little sprouts that we call "eyes". They do not see. Needles also have their "eye" for the thread. And it seems to me that hurricanes have that "eye" in the middle. Curious, isn't it?

In all these cases we use "eye" to talk about something that, well, looks like an eye or something like that. It's not that they actually see. It's just a way of speaking. Although it is not entirely clear why we started calling them that.