The interview included demographic characteristics such as age, tendency of the subjects' skin to tan or sunburn, host characteristics, including eye and hair color, number of large nevi, presence of freckles, medical history, including use of corrective lenses and reproductive history for women, exposure to UV or black lights (sunlight was excluded), and vacation and leisure-time activities. Among other factors, we also included questions about use of cigarettes, coffee, tea, and alcohol, service in the military, and whether the subjects were more likely to be automobile drivers or passengers. Hair and eye color were assessed by asking subjects what their natural hair color was at age 20, and whether they had blue, green, gray, hazel, or brown eyes. they had on their entire body including any that mayhave been removed. Eye diseases were assessed by asking subjects "Before the diagnosis of your eye tumor, were you ever treated by a physician for:" followed by the various conditions of interest such as "an injury that penetrated your eye, an injury or blow to your eye thatdid not penetrate, a sty infection, an infection in your eye other than a sty, glaucoma, uveitis" and, "Were you ever diagnosed with any other condition that affected your eyes?" Answers were coded by each typeof condition, e.g., retinal detachment, welding burn, iritis, and then grouped when appropriate.