Blind as a bat

[M.T.Vessel]

How do we Know that bats are blind?

[Unabashed]

We know that bats are blind because there have been a series of tests performed to establish this. With all the technoligy we have to find out if humans are blind why would'nt we know......?

[addied]

The fact they have a sonar system is very strong evidence that they can't see to navigate.

[M.T.Vessel]

I agree with Einstein

[snaykz]

I remember hearing that this phrase was something of a fallacy and that bats actually have reasonable eyesight (although not as good as ours). The fact that they navigate by sonar has led people to underestimate their visual skills.

[Leda74]

Bats are not blind - they just don't have very good eyesight, as it's not required for a nocturnal creature that hunts using sonar.