Diabetic retinopathy is a complication of diabetes involving the blood vessels that nourish the retina of the eye, and the leading cause of blindness among adults. Approximately 25% of current diabetics have some form of the disease. Left untreated, diabetic retinopathy can result in severe visual loss, including blindness. Since there is no pain or other external symptoms, changes in the retina can go unnoticed unless detected by an eye examination by an eye specialist. All people diagnosed with diabetes are at risk.