Why is the blind spot called blind spot

Because you can't see it

you can't see the spot

Explanation:

that is why it's called a blind spot, example-humans can see in the front, right side, left side, up, down but we can't see behind our head-this is called a blind spot! (be careful when you sneak up on some people-there reflexes will beat the mess outta you XD) : D another example is a horse:can not see behind them and if provoked you'll feast on a badly dangerous kick! (brain list? if not then have a good day! : 3)