Heterochromia— different color of the iris of the right and left eyes, or uneven coloring various sections of the iris of one eye. It is the result of the relative excess or lack of melanin. The color of the eyes, that is the color of the irises, is determined primarily by the concentration and distribution of melanin. Heterochromia is more common in animals than in humans. It usually leads to a blue color of one eye. Different eye colors can be found in completely white cats or cats with a large percentage of white in the color, especially in breeds such as the Turkish Angora and Turkish van. Heterochromia is not so often, but there are individuals with a black color. From odd-eyed cats, as a rule, one eye is orange, yellow or green and the other blue eyes.