A study by experts at the University of Copenhagen found that every single person with blue eyes shares a common ancestor.

Blue eyes are caused by a gene mutation. For years, researchers had searched for it on the OCA2 gene. The OCA2 gene determines how much brown pigment is in our eyes. But what they were looking for ...

Just as the MC1R gene determines your hair color, a single gene, OCA2, is 75% responsible for your eye color, Dr. Kaplan says. For eye color, the OCA2 gene determines how much melanin is in the ...