Heterochromia is uncommon in humans, but quite common in dogs (such as Dalmatians and Australian sheep dogs), cats, and horses.

Most cases of heterochromia are hereditary, caused by a disease or syndrome, or due to an injury. Sometimes one eye may change color following certain diseases or injuries.

Specific causes of eye color changes include:

• Bleeding (hemorrhage)
• Familial heterochromia
• Foreign object in the eye
• Glaucoma , or some medications used to treat it
• Injury
• Mild inflammation affecting only one eye
• Neurofibromatosis
• Waardenberg syndrome

Consult your health care provider if you notice new changes in the color of one eye, or two differently colored eyes in your infant. A thorough eye examination is needed to be sure this isn't a symptom of a medical problem.

Some conditions and syndromes associated with heterochromia, such as pigmentary glaucoma, can only be detected by a thorough eye exam.

Your health care provider may ask the following questions to help evaluate the cause:

• Did you notice the two different eye colors when the child was born, shortly after the birth, or recently?
• Are any other symptoms present?

An infant with heterochromia should be examined by both a pediatrician and an ophthalmologist for other possible problems.

A complete eye examination can rule out most causes of heterochromia. If there doesn't seem to be an underlying disorder, no further testing may be necessary. If another disorder is suspected, diagnostic tests, such as blood tests or chromosome studies , may be done to confirm the diagnosis.