U.S. Air Force Capt. John Kauderman, 20th Aerospace Medicine Squadron optometrist, uses a slit lamp to examine a patient’s eye at Shaw Air Force Base, S.C., June 14, 2017. Kauderman used the instrument, which magnifies and directs light into the eye, to evaluate for disease or abnormality. (U.S. Air Force photo by Airman 1st Class Kathryn R.C. Reaves)