Do you have blue eyes? We talked to experts to discover curious facts about baby blues, including whether your biological family is bigger than you ever imagined.

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.

These small primates have the largest eyes of any mammal, relative to their body size. Each eye is about the same volume ... from gold in the summer to blue in the winter. The technique allows them to ...