Heterochromia: Why Are My Eyes Different Colors?

By Dr. Russel Lazarus
hetero

What do actors Mila Kunis and Kate Bosworth have in common, other than being celebrities? They both have heterochromia. 

Perhaps the most famous celebrity with heterochromia, actress Kate Bosworth has one blue eye, and one eye that is partially hazel.

Heterochromia occurs when the eyes have different colors, this condition affects less than 1% of the population.

What is heterochromia?

Heterochromia is a condition that affects the iris of the eye, the pigmented part of the eye that surrounds the pupil.

This rare condition can be characterized by two different colored eyes, one eye appearing darker than the other, or with part of the iris appearing different than the rest.

All cases of heterochromia should be examined by an eye doctor because although most cases are harmless, in rare cases, heterochromia can signal an underlying condition.

Types of heterochromia

Heterochromia can present in three different ways:

  1. Complete heterochromia (heterochromia iridis) is when one iris is a different color than the other.
  1. Segmental (partial) heterochromia (heterochromia iridum) is when the iris contains different colors that present in a wedge pattern. This can occur in one or both eyes and may look different in each eye, with one iris containing a larger “wedge” of the secondary color than the other.
  2. Central heterochromia is when the outer ring of the iris is a different color from the rest of the iris. It is considered the most uncommon, and usually occurs in both eyes.

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Contact an eye doctor near you if you notice a color difference between you or your child’s eyes.

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What causes heterochromia?

Most cases of heterochromia are congenital, but in rare cases, it can also be acquired.

Congenital heterochromia

Congenital heterochromia is typically caused by a genetic mutation unrelated to any underlying condition, and only affecting the amount of pigment cells within each iris.

In rare cases, congenital heterochromia can occur from a medical condition, such as:

  • Benign heterochromia
  • Hirschsprung disease
  • Von Recklinghausen disease
  • Bourneville disease
  • Piebaldism
  • Bloch-Sulzberger syndrome
  • Waardenburg syndrome
  • Sturge-Weber syndrome
  • Parry-Romberg syndrome
  • Horner’s syndrome

Acquired heterochromia

Acquired heterochromia occurs when an outside factor has caused the color of the eye to change.

This is less common than the genetic form, but can result from:

How is heterochromia diagnosed?

During a comprehensive eye exam, your eye doctor will try to determine the underlying causes of why one eye could be different to the other. Be sure to inform your eye doctor if you or your child is showing any other symptoms or if there have been any recent changes to the vision or eye comfort.

Your eye doctor may order blood tests and/or genetic tests to rule out an underlying condition.

Can heterochromia be treated?

Heterochromia can be treated if there is an underlying condition or disease. By treating the underlying cause, the heterochromia may disappear on its own.

LEARN MORE: Guide to Eye Health

Schedule an appointment with an eye doctor near you if you are concerned about the color of your or your child’s eyes.

Heterochromia is a condition that affects the iris of the eye, the pigmented part of the eye that surrounds the pupil.

All cases of heterochromia should be examined by an eye doctor because although most are harmless, in rare cases, heterochromia can signal an underlying condition.