An infrared light illuminates U.S. Army Sgt. 1st Class Bobby M. Scharton, a platoon sergeant with 17th Fires Brigade, 7th Infantry Division, during a sleep study at Madigan Army Medical Center, Joint Base Lewis-McChord, Wash., Nov. 22, 2013. Physicians use data from the studies to diagnose severe sleep disorders like sleep apnea and insomnia.