Meaning
Having very poor eyesight; by extension, stubbornly failing or refusing to notice something obvious. The first sense concerns literal vision, the second applies the image to wilful obliviousness, as with someone who cannot see the evidence in front of them. Informal and often self-deprecating about poor eyesight; the wilful-ignorance sense can sound insulting. Regional use: General English.
Origin
The premise is ancient: observers took bats' darting, erratic flight as proof of poor sight, and Aristotle compared the eyes of bats to the blaze of day. English animal similes of blindness long predate the bat version - the mole comparison goes back to Greek proverbs, and the OED groups the bat phrase with older parallels such as 'blind as a beetle' and 'blind as a mole'. Blind-style comparisons in the OED run back to around 1000 CE, and the first reference including bats is late 1500s: John Harvey's A Discursive Problem Concerning Prophesies (1588) reads 'as blinde, as moules, or bats'. Zoologically the premise is false - bats can see, and many species also navigate by echolocation.
Research Sources
References used to check this entry’s meaning, history, or documented forms.
Variants
- as blind as a bat
- blind as a beetle
- blind as a brickbat
- blind as a mole
Usage Examples
- Without my glasses I'm as blind as a bat, so please read the departure board for me.
- He is blind as a bat where his business partner is concerned; the missing invoices are right there in the ledger.
- The labels shrank so much this year that even sharp-sighted shoppers feel blind as a bat in the supermarket aisle.