Odd-eyed cat and heterochromia iridum
Our eye colors vary because of different concentrations and distributions of pigments, called melanin, deposited in the iris. Brown eyes are rich in melanin, while blue eyes lack this pigment. Heterochromia iridum describes a pair of eyes with mismatching colors. It is rare in people, but it frequently occurs in animals, such as cats, especially those with white furs that possess a gene that can mask out other color genes. A so-called “odd-eyed cat” has one blue eye, due to the prevention of melanin from reaching that eye during its development, and another regular color in the other eye, such as green, as in the photo.