Actually there are some bats who really do use their eyes. Some species of bats have very large and round eyes to be able to see in the dark while their ears are smaller than the size of their heads. Thus this adaptation shows they use their eyes rather than their ears like other bats.
Other bats that you say are blind use another source of "sight" called echolocation. This is like the sonar of a dolphin or submarine to detect other things in the water only this form is on dry land. Bats emit a loud sound (or that little squeak you hear all the time when they fly around you) and when those sound waves bounces off of an object and comes back to the bat, it can know the location of obstacles or insects. Bats can use the echo that bounces off and use that to obtain information about that object or insect, like what size it was, how it moves, all that good information and they use that to their advantage whenever they're obtaining food or dodging trees and light poles. But while vision is not important to the bats during the night, hence the large ears but small eyes, the bats really can see so they're not really blind as people think.
· 1 decade ago