While they may look similar to blue eyes, they often have a silvery or smokey appearance, sometimes with hints of green or hazel. Only about three percent of people worldwide have this rare eye color.

Heterochromia is just a fancy word for different-colored eyes. While it's quite rare, a surprising number of famous people seem to have been afflicted with it.

According to Healthline, 45% of Americans have brown eyes, 27% have blue eyes, 18% have hazel eyes and 9% have green eyes. That means there are tens of millions of blue-eyed people in the U.S. alone.