Heterochromia of the skin is excess or lack of melanin (pigment) in the skin cells, making the skin discolored or be multiple shades. It can be different patches of skin anywhere, the hands, back, chest, even your head! Though some places may be unnoticeable, but others (like in the picture below) are very noticeable.
Some people confuse it as a birthmark, but birthmarks can be heterochromia. Some birthmarks are from extra melanin, while others are clumped blood vessels or blood vessels that grow irregularly. So it could be heterochromia, but not very likely.
Some people confuse it as a birthmark, but birthmarks can be heterochromia. Some birthmarks are from extra melanin, while others are clumped blood vessels or blood vessels that grow irregularly. So it could be heterochromia, but not very likely.
Heterochromia is the difference in coloration of the iris, skin and hair. It can be of two types in the eye (central and sectoral). Lack of or access melanin are the causes for all and sometimes birthmarks are mistaken as heterochromia and it could just be thinning hair. Heterochromia is not only humans, it can be in cats, it often is, and dogs, which is less often. Any one (or cat/dog) can have heterochromia weather its in their genetics, or they pick it up on the way.