It may seem merely a cliche born of centuries of educated people straining their eyes in dimly-lit libraries, but new genetic research suggests those who wear glasses really are more intelligent.

Researchers at the University of Edinburgh analysed the genetic data of more than 44,480 people.

They found that, overall, those who were more intelligent were nearly 30 per cent more likely to have genes indicating they require reading glasses than those who scored poorly.

Published in the journal Nature Communications, the research also linked higher cognitive ability to genes known to play a part in better cardiovascular health.

The results are based on the most thorough investigation of intelligence genes of its kind to date.