Like most human traits, blue eyes are determined by genes, and no two people have exactly the same hue. It works a lot like ...

It seems a little unfair. The ladies love blue eyes, and babies already have a cuteness advantage. The iris is the muscular ring around the pupil. And its color depends on a protein called melanin ...

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.