Optometry
U.S. Air Force Capt. Sean Berensen, 31st Aerospace Medicine Squadron optometrist, tests a patient’s eyes, July 7, 2015, at Aviano Air Base, Italy. The optometry clinic uses a phoropter, which contains different lenses, to determine a patient’s glasses prescription. (U.S. Air force photo by Senior Airman Areca T. Wilson/Released)