Actually, there are three classes of medical certificate for pilots. As to third-class medical certificate, the distant vision must be 20/40 in each eye to qualify for a third-class medical certificate. Near vision must be at least 20/40 for each eye when sight is measured at 16 inches. This way of measuring replicates conditions in the cockpit for near-vision tasks such as reading a chart. For any of the certificates, you must be able to see colors and you can't have an eye condition that interferes with eyesight. Moreover, when it comes to the first-class and second-class medical certificates, your distant vision must be 20/20 in each eye, and both near and intermediate vision must be at least 20/40 in each eye. The near vision must be measured at 16 inches. If you're age 50 or older, you must possess at least 20/40 vision at 32 inches, as well. This ensures intermediate vision is adequate for looking at cockpit flight instruments. Pilots also must have a normal field of vision to earn a first- or second-class medical certificate. Hope this helpful.