le with light eye colors, such as blue, green, and hazel, are more vulnerable to hearing damage than are people with brown or black eyes. Reasons for the greater susceptibility among light-eyed blacks remain unclear, but melanin according to studies, melanin may have something to do with it. Researchers have determined that the inner ear produces extra melanin when stressed by noise. Melanin, however, may both protect and harm hearing. It sometimes cleans up harmful molecules, but at other times, it contributes to their creation.Melanin is not only linked with hearing, but also with hair color. The smallest amount of melanin in hair will make hair appear black. This is illustrated by the fact that those who are lightly pigmented in the skin can still have black hair. Hair color of light-skinned people ranges from black to brown to blond. However, in dark-skinned people, there appears to be an intense selection for dark hair. The hair color variants of light-skinned people are due to the two melanins--eumelanin and phaeomelanin, just as in the skin. Red hair contains melanosomes that contain phaeomelanin in high concentrations. Thus hair color is determined by various proportions of both eumelanin and phaeomelanin. Eye color, on the same hand, is determined by the concentration and location of melanin in the iris of the eye. A large amount of melanin is present in the iris of brown- or black-eyed individuals. Light eyes such as blue, green, or hazel are the product of dispersed melanosomes, which are not as concentrated as in dark-eyed individuals. Melanin found in the iris of the eye functions as a protector of cells making up the iris and retina, similar to melanin's protection of the skin. Iris and retina cells of individuals with light eyes are much more sensitive to bright light than corresponding cells from dark-eyed individuals. Those with pigmented skin have the highest counts of melanocytes in the genitalia and nipp...
