Good diabetic doctors in bangalore Diabetic retinopathy is a diabetes complication that affects the eyes. It's caused by damage to the blood vessels of the light-sensitive tissue at the back of the eye (retina). Here's an overview of the condition: Causes High Blood Sugar Levels: Prolonged periods of high blood sugar can cause damage to the small blood vessels in the retina. Duration of Diabetes: The longer someone has diabetes, the higher the risk of developing retinopathy. Stages Mild Nonproliferative Retinopathy: Small areas of balloon-like swelling in the retina's blood vessels. Moderate Nonproliferative Retinopathy: Blood vessels that nourish the retina are blocked.