Eye color was also found to be a risk factor in two other studies of uveal melanoma (2, 3). The color of the iris is determined by degree of pigmentation, with relatively little melanin pigment producing a blue or gray iris and considerably more, a brown iris (9). Melanin in the iris can absorb UV as well as visible light (9). The protective effect of brown eyes may result from the ability of brown eyes to filter more UV light than light-colored eyes.