Diabetic retinopathy is a complication of diabetes 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). In the early stages, diabetic retinopathy may cause no symptoms or only mild vision problems. But as it progresses, it can lead to severe vision loss and even blindness if left untreated. There are two main types of diabetic retinopathy: Nonproliferative diabetic retinopathy (NPDR): In this early stage, small blood vessels in the retina leak blood or fluid. This leakage may cause the retina to swell or form deposits called exudates. NPDR typically doesn't cause vision loss unless it progresses to a more severe stage. Proliferative diabetic retinopathy (PDR): In this advanced stage, new blood vessels grow in the retina and into the vitreous gel, which can lead to serious vision problems. These new blood vessels are fragile and prone to bleeding, causing the vision to become blurry or even causing com...