A physically active lifestyle may help protect your eyes from glaucoma, according to a new study. Glaucoma, a leading cause of blindness, typically develops when fluid pressure inside the eye rises and damages the optic nerve. In this study, researchers looked at the association between physical activity and eye pressure in 5,650 men and women aged 48 to 90 in Britain. The participants were evaluated between 1993 and 1997 and again between 2006 and 2010.