Heterochromia is a condition present in some humans and animals where one iris is a different color than the other. The iris is a thin circular structure that surrounds your pupil and contains pigment or melanin, which gives our eyes their distinct color. The amount of melanin that has developed in the iris at birth and shortly after determines one’s eye color. Blue eyes contain the lowest amount of melanin while brown eyes have the most.
While heterochromia commonly causes two different colored irises, it is not always so black and white so to speak. Heterochromia diagnoses can have a few variations such as:
- Complete heterochromia – This is the type most people think of when they imagine heterochromia. This condition is when one iris is a different color from the other, such as one blue eye and one brown eye.
- Partial or segmental heterochromia – This type of heterochromia is when only a portion of the iris of one eye has a different color than the rest of the iris in the eye, meaning a person may have a mostly blue eye with a portion of it brown.
- Central heterochromia – This type refers to when the color near the pupil is different from the outer parts of the iris. It is common for the center color to spike or radiates out from the pupil toward the middle of the iris such as a predominately brown eye with a blue center ring that radiates out.
In most cases, heterochromia is benign and not a result of a disease or condition and does not affect one’s vision. An infant can be born with heterochromia or develop it within the first few months after birth as the iris attains its full amount of melanin. This is often a result of genetics and can be hereditary. This form of heterochromia is known as congenital heterochromia.
You can also develop heterochromia as an adult as a result of injury, trauma, illness, or certain medications. This condition is known as acquired heterochromia.
Regardless of whether you developed the condition as an infant or later in life, it is important to visit an optometrist or ophthalmologist so they can conduct a full comprehensive exam. Your doctor will be able to confirm the appearance of heterochromia and look for any underlying causes or symptoms that may be harmful to your vision or general health. Most cases are benign with no underlying causes or harmful symptoms, but it is best to have a proper diagnosis.
Treatment for heterochromia depends on the diagnosis. If the condition is benign and not the result of a harmful cause and has no effect on vision or the general well being of the patient, treatment may not be needed. Otherwise, the treatment will focus on treating the cause of the heterochromia.
For more information on heterochromia, please contact St. Lucy’s Vision Center.