Maj. Charles Malone, 28th Medical Operations Squadron optometrist, performs a slit lamp test on Master Sgt. Mark Slater, 28th MDOS NCO in charge of optometry, at Ellsworth Air Force Base, S.D., Oct. 24, 2014. Slit lamps provide the optometrist with a magnified view of the internal and external portions of the eye to identify cuts, scrapes, tears, foreign objects or infections. (U.S. Air Force photo by Senior Airman Zachary Hada/Released)