melanin

a dark brown PIGMENT found in the SKIN and HAIR and also in the choroid layer of the EYE . Melanin is contained and produced within cells, known as melanocytes, in the dermis layer of the skin. When the skin is exposed to hot sunshine, more melanin is produced, giving a 'suntan'. In dark-skinned races, more melanin is produced by greater activity of the melanocytes, and it helps to protect the skin from harmful ultraviolet radiation.