Credit: Tofayel Tonmoy

A UK study, published in New Scientist, found blue-eyed individuals were better able to read in dimmer lighting conditions compared with brown-eyed subjects.

Liverpool John Moores University researchers Dr Kyoko Yamaguchi and Faith Cain assessed 40 participants who sat in darkness for 30 seconds before the lighting was increased until they were able to read letters on a wall 3m away. On average, blue-eyed subjects needed 0.7 lux of ambient lighting, compared with 0.82 lux for those with brown eyes. “It’s likely depigmented irises provide an adaptive advantage,” said Dr Yamaguchi.