Another study showing the cognitive benefits of meditation has revealed benefits to perception and attention. The study involved 30 participants attending a three-month meditation retreat, during which they attended group sessions twice a day and engaging in individual practice for about six hours a day. The meditation practice involved sustained selective attention on a chosen stimulus (e.g., the participant’s breath). By midway through the retreat, meditators had become better at making fine visual distinctions, and better able to sustain attention during the half-hour test, compared to matched controls. Those who continued practicing meditation after the retreat still showed improvements in perception when they were retested about five months later.
Visual perception heightened by meditation training
 Intensive Meditation Training Improves Perceptual Discrimination and Sustained Attention. Psychological Science. 21(6), 829 - 839.(2010).