Complete heterochromia: This is caused when the color in the iris of one of the eyes varies completely from the color of the iris of the other eye. This can occur in either or both the pupils. For instance, one eye may be green, while the other is brown.
Partial or sectoral heterochromia: As suggested by the name, only a part or sector of a pupil is differently colored from the rest of it. This can occur to either or both the pupils. For example, a certain part of the pupil may be blue, while the rest is dark brown.
Central heterochromia: Here, the border of the pupil is a different color than the rest of the iris. Spikes of the central color emanate from the pupil towards the middle of the iris. This results in multiple colors in the same eye. For example, a green ring around the pupil and blue in the iris.
Acquired heterochromia: This usually develops in later years of life due to an injury, certain diseases, and medication.
Causes of heterochromia
Our eyes owe their color to melanin pigment deposits that develop in the iris, located at the center of the eyes. Dark brown eyes are rich in melanin deposits, green and blue eyes indicate a lower deposition of this pigment in the iris.
A lack of distribution and concentration of melanin in the pupils and/or iris causes heterochromia. The location of concentration of melanin in the pupils and/or iris determines the type of heterochromia that will become visible.
A vast majority of cases of heterochromia amongst are benign. They are often not a manifestation of an underlying medical condition.
According to another study, most of the cases are not genetic, even if this is possible.
In some cases, the health condition may signal serious diseases, such as