Blue, green, brown, and hazel are all common eye colors. Usually both of a person’s eyes are one uniform color. But, in some cases a person might have two different colored eyes, or one partially different colored eye.

This condition, called Heterochromia, is where the person suffering from the condition has two different colored eyes, one partially different colored eye, or eyes that have two different colors in them.  Heterochromia is typically caused by an unequal concentration or distribution of melanin.

“Many babies are born with blue eyes and may turn brown or other colors.  My one eye turned brown and the other eye turned mostly brown, but about 1/3 of my eye stayed blue,”  Joanne Ullman, secretary at Seth Paine Elementary School, said.

A different colored eye can be caused by bleeding, a foreign object in the eye, injury to just one or part of an eye, Neurofibromatosis, Waardenburg syndrome, inflammation in one eye, genetics, or other factors.

“ [My optometrist] said we may never know the exact reason.  Sometimes this condition is inherited, but no one else in my family (that I know of) has different color eyes,” Ullman said. “There were 5 people in my family.  My mom, my 2 brothers and my sister all have dark brown eyes.  My dad had light blue eyes. He passed away when I was 15 so I when I see the little bit of blue in my eye I always think of my dad and it makes me feel close to him.”

The condition itself is quite rare, affecting about 11 per 1,000 people, or roughly 1.1% of the population.  Despite these odds, many celebrities and historical figures were rumored to have had it, including Mila Kunis, Alexander the Great, Benedict Cumberbatch, and Simon Pegg.