Deceased (356 BC–323 BC)

Although king of ancient Macedonia for less than 13 years, Alexander the Great changed the course of history. One of the world’s greatest military generals, he created a vast empire that stretched from Macedonia to Egypt and from Greece to part of India. This allowed for Hellenistic culture to become widespread.

Alexander the Great, depicted in typical Hellenistic style in this alabaster bust from Egypt, was probably physically ordinary. By most accounts, he was short and stocky. Many historians also think Alexander had heterochromia—one eye was brown, the other blue.

Cleopatra of Macedonia (c. 355/354 BC – 308 BC), or Cleopatra of Epirus, was an ancient Macedonian princess and later queen regent of Epirus. The daughter of Philip II of Macedon and Olympias of Epirus, she was the only full sibling of Alexander the Great.

Heterochromia is when a person’s irises, the pigmented portion around the pupil, are different colors or partially different colors. Kunis suffered from chronic inflammation of the iris for a long time. “I was blind in one eye for many years, and no one knew,” she told Cosmopolitan in 2011.

Perhaps the rarest eye color is not one color at all, but multicolored eyes. This condition is called heterochromia iridis. A person can be born with this condition, it can develop in infancy, or it can develop as a symptom of a systemic disease or after an injury to the eye.

Heterochromia is fairly uncommon, occurring in less than 1 percent of the population. It can be caused by several factors and present itself in different ways.

Central heterochromia may be a rare condition, but it’s typically benign. In most cases, it doesn’t affect vision or cause any health complications.