All blue-eyed people have one ancestor in common, born around 6,000 to 10,000 years ago. Blue eyes are caused by a gene mutation. For years, researchers had searched for it on the OCA2 gene.

The recent study has unveiled a remarkable genetic link shared by people with blue eyes. Astonishingly, over 99.5 per cent of blue-eyed participants in the study have the same tiny mutation ...