[ELI5]Why is it that sometimes things appear more clearly in our peripheral vision than when it is directly looked at?

Question

For example, when looking up the night sky, I can spot more stars in my peripheral vision. But some of them disappear when I look at that very spot directly.

In: 7

Answer 1

Peripheral vision is a pure anti predator survival tool which is why it’s very sensitive, it may just keep you alive..