Eye color is a polygenic phenotypic trait determined by two factors: the pigmentation of the eye's iris and the frequency-dependence of the scattering of light by the turbid medium in the stroma of the iris See more

A 1997 study of White Americans found that eye color may be subject to change in infancy, and from adolescence to adulthood.
17% of children experienced a change of eye color from early childhood to adulthood, and of … See more

The most important role of melanin in the iris is to protect the eyes from the sun's harmful rays. People with lighter eye colors, such as blue or green, have lessened protection from the sun, and so need greater protection from the sun's rays than those … See more

Although people with lighter eye color are generally more sensitive to light because they have less pigment in the iris to protect them from sunlight, there is little to no evidence that eye … See more

Eye color is an inherited trait determined by multiple genes. These genes are sought by studying small changes in the genes themselves … See more

Brown
Almost all mammals have brown or darkly-pigmented irises. In humans, brown is by far the most common … See more

The limbal ring is also a feature of the iris contributing to eye color, appearing as a darkened, occasionally black region encircling the iris resulting from a manifestation of the optical properties of the corneal limbus. Limbal rings are not present in all … See more