If a bat uses echo at night so can we say their vision is constricted somewhat or they see fully?

I saw a documentary on vampire bats narrated by Jeremy Irons. And on that doc I saw that bats are nocturnal as we all know and they use echo system to navigate through the night.

Are the eyesights of the bats somewhat constricted because of evolution and they use echo instead? How do they know from the returned echo how far they are from the object about to be collided with and move away from that? Do they figure out that precise location of the object near them by the lower, higher and medium pitch of the returned echo?