Meaning
Having extremely poor eyesight, or, in a figurative sense, being completely unaware of something obvious that is happening right in front of you.
It is used both literally, to describe someone who cannot see well, and figuratively, to criticize someone who fails to notice or understand an evident fact or situation.
Origin
The phrase is based on a common misconception that bats are blind because of their nocturnal habits and their use of echolocation to navigate in the dark. In reality, most bat species can see reasonably well, but the folk belief that they are sightless was widespread enough by the sixteenth century to give rise to this now-fixed English simile for very poor vision or obliviousness.
Examples
I cannot read the small print without my glasses, I am as blind as a bat these days.
He walked right past his own car in the parking lot, as blind as a bat.
She is as blind as a bat when it comes to her son’s obvious problems at school.
A: Did you notice she has been avoiding you all week?
B: No, I guess I have been as blind as a bat.
Frequently asked questions
What does 'As blind as a bat' mean?
Having extremely poor eyesight, or, in a figurative sense, being completely unaware of something obvious that is happening right in front of you.
It is used both literally, to describe someone who cannot see well, and figuratively, to criticize someone who fails to notice or understand an evident fact or situation.