Are bats blind?

No. Bats are not blind. Their eyes are small but tuned to very low light, so many species see well in near darkness, and some fruit bats see well in daylight too. Many bats also use echolocation, so sight is one tool among several.

What's actually true

Bats aren't blind, and many see well in near darkness. "Blind as a bat" gets it backwards. Bats have small eyes, but their vision is tuned for very low light, letting them see in conditions that look pitch black to us. What they lack is sharp, colorful daytime vision. Many species also use echolocation, so sight is just one of their tools.

Takeaway: Many bats see well in dim light, and some fruit bats see well in daylight too.

Why people believe it

Bats fly at night, have small eyes, and are famous for echolocation, so it is easy to conclude they navigate by sound because they cannot see. Their erratic flight at dusk and the occasional bat that bumps into things indoors seem to confirm it. The phrase 'blind as a bat' then turned a guess into a saying. Echolocation and vision are not either-or, though: bats use both depending on the light and the task.

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