This condition is relatively rare in humans. However, heterochromia appears quite commonly in dogs (such as Dalmatians and Australian sheep dogs), cats, and horses.

Heterochromia in humans can appear either as a hereditary trait unassociated with other disease, or as a symptom of various syndromes. Rock star David Bowie has heterochromia.

• familial heterochromia (autosomal dominant transmission)
• Waardenberg syndrome (congenital and is autosomal dominant)
• neuroblastoma (as a result of cervical sympathetic nerve compression)
• pigmentary glaucoma
• neurofibromatosis (may cause the affected iris to darken)
• acquired heterochromia is a change in the color of the iris resulting from trauma, hemorrhage, glaucoma, or intraocular foreign body.

If you notice new changes in the color of one eye or that your infant has two different colored eyes, consult your health care provider to be sure that this isn't a symptom of a medical problem. A complete eye exam conducted by an ophthalmologist (eye doctor) is also recommended.

If you or your physician notice heterochromia, a referral to an ophthalmologist is recommended. Some conditions and syndromes associated with heterochromia, such as pigmentary glaucoma can only be detected by a thorough ophthalmic exam.

The medical history will be obtained and a physical examination performed.

Medical history questions documenting heterochromia in detail may include:

• Were the two different colored eyes noticed when the child was born, shortly after the birth, or is the condition of recent onset?
• Exactly which eye appears which color?
• Are any other symptoms present?

PHYSICAL EXAMINATION
An infant with heterochromia should be examined for other problems.

Children and adults should receive a complete eye examination to detect any disorders that need treatment. For example, pigmentary glaucoma and intraocular metallic foreign bodies may go undected without a complete eye exam.

DIAGNOSTIC TESTS
A complete eye examination can rule out (or in) most causes of heterochromia. If there is no indication that there is a disorder, no further testing may be necessary. If another disorder is suspected, diagnostic tests may be performed to confirm the diagnosis. This may include various blood tests, chromosome studies, or others.

AFTER SEEING YOUR HEALTH CARE PROVIDER
If a disorder was diagnosed, you may want to note that diagnosis in your personal medical record. If the heterochromia is an inherited trait, you may also want to note this in your personal medical record.