Between 8% and 10% of people worldwide have blue eyes, and this feature is most common in Europe, especially Scandinavia. People with blue eyes have the same genetic mutation that causes eyes to produce less melanin. This mutation first appeared in a person living in Europe about 10,000 years ago, and that individual is a common ancestor of all blue-eyed people today. People with blue eyes might see better at night but have more trouble with glare.

Source: Healthline