Homokromia

Homokromia is a rare congenital condition characterized by an individual having irises of two different colors. This difference can be striking, with one eye appearing entirely different from the other. The most common form is complete heterochromia, where each iris is a distinct color. Less common is sectoral heterochromia, where a portion of one iris is a different color from the rest of it. Segmental heterochromia is similar but involves a wedge-shaped section of an iris.

The varied coloration in homokromia is due to differences in the concentration and distribution of melanin pigment in the iris stroma. Melanin, the same pigment that determines skin and hair color, is responsible for eye color. In homokromia, there's an imbalance in melanin production or deposition in one or both eyes. This can occur due to genetic factors, affecting melanin distribution during embryonic development.

In most cases, homokromia is harmless and does not affect vision. It is often a purely cosmetic trait. However, in some instances, homokromia can be a symptom of an underlying medical condition. These conditions include certain genetic syndromes like Waardenburg syndrome, or acquired causes such as inflammation of the iris (iritis), or trauma to the eye. If homokromia appears later in life, it is important to consult an ophthalmologist to rule out any secondary causes. Diagnosis is usually made through a visual examination and sometimes requires further investigation depending on the suspected cause.