blind

a blind alley a course of action that does not deliver any positive results.

2013New Statesman They are well aware of the gilded complacency that dulls Cameron's appeal, especially to squeezed households. But they want that flaw to discredit the rest of his project to reform the party. According to this view, the Cameroons led the Tories down a blind alley of cosmopolitan elitism.

as blind as a bat having very bad eyesight. informal

☞ This expression probably arose from the bat's nocturnal habits and its disorientated flutterings if disturbed by day. The poor eyesight of bats (and less frequently, moles) has been proverbial since the late 16th century.

a blind bit of - the smallest bit of-; no - at all. informal

2007Daily Telegraph His two great fears were that the technology might not be robust enough to use in casework, and that, even if it were, no one would take a blind bit of notice.

a blind date a social meeting, usually with the object of starting a romance, between two people who have not met each other before.

the blind leading the blind a situation in which the ignorant or inexperienced are instructed or guided by someone equally ignorant or inexperienced.

☞ This phrase alludes to the proverb when the blind lead the blind, both shall fall into the ditch, quoting Matthew 15:14.

a blind spot

1 an area into which you cannot see.

2 an aspect of something that someone knows or cares little about.

☞ These general senses appear to have developed from a mid-19th-century cricketing term for the spot of ground in front of a batsman where a ball pitched by the bowler leaves the batsman undecided whether to play forward to it or back.

blind someone with science use special or technical knowledge and vocabulary to confuse someone.

rob someone blind: seerob.

swear blind: seeswear.

turn a blind eye pretend not to notice.

☞ This phrase is said to be a reference to Admiral Horatio Nelson (1758–1805), who lifted a telescope to his blind eye at the Battle of Copenhagen (1801), thereby ensuring that he failed to see his superior's signal to discontinue the action. A less usual version, referring directly to this story, is turn a Nelson eye.