Vision is something most of us take for granite.  There are many reasons that vision may fail; age-related mascular degeneration, dry eye syndrome, glaucoma, injury and others.  Low vision or blindness can affect any age, and children with developmental disabilities may have low vision just as older persons may have cataracts.  The world Health Organization defines “low vision” as visual acuity between 20/70 and 20/400, with the best possible correction, or a visual field of 20 degrees or less.  “Blindness” is defined as a visual acuity worse than 20/400, with the best possible correction.  Someone with a visual acuity of 20/70 can see at 20 feet what someone with normal sight can see at 70 feet.  Someone with visual acuity of 20/400 can see at 20 feet what someone with normal sight can see at 400 feet. Normal visual field is about 160-170 degrees horizontally.

With diabetes, a person needs to watch for Retinopathy.  Diabetes accounts for over 12,000-24,000 cases of blindness each year.  Maintaining good blood sugar and blood pressure control can substantially reduce the risk and progression of diabetic retinopathy (American Diabetes Association, 2006).  If you have proliferated diabetes retinopathy or severe non proliferated diabetic retinopathy, vigorous aerobic or resistance exercise may be contraindicated because of the risk of triggering vitreous hemorrhage or retinal detachment (American Diabetes Association, 2006)