US Navy 080812-N-9774H-106 Hospitalman Michael Hagglund, an optometrist technician embarked aboard the amphibious assault ship USS Kearsarge (LHD 3), uses an auto refractor to help determine eye prescriptions on a patient at Ju
Szerző: U.S. Navy photo by Mass Communication Specialist 1st Class Emmitt J. HawksForrás: commons.wikimedia.org