Any applicants for national endorsement/ certification or qualified deck rating are required to have uncorrected–in other words, natural–vision of at least 20/200. That vision also must be correctable to 20/40 or better in both eyes. The applicant must also possess a horizontal field of vision equal to at least 100 degrees in each eye. Aside from the clarity of vision, they must also be able to distinguish between green, blue, red, and yellow.