As Blind As A Bat Meaning

If someone is as blind as a bat, they are nearly or completely blind or they are unwilling to recognize problems or bad things.

This is a simile which is based on the erroneous idea that bats cannot see properly. In fact, bats are not blind; they use vision to navigate, especially for long distances. In addition to their ability to see, they use a sophisticated built-in sonar system, called echolocation.

Example: 1. Without her glasses, she is as blind as a bat.
2. He is as blind as a bat when it comes to his wife's shameful behavior