Diabetic retinopathy (DR) mostly affects the people as a result of diabetes and it leads to blindness. Diabetic retinopathy (DR) affects the eyes as a result of increased blood glucose levels. Among people in the 70-year-old age group, 50% of deaths are associated with diabetes. Detection of diabetes at a early stage and taking a proper treatment can reduce vision loss among the patients. Once DR symptoms are recognized, the severity of the disease must be assessed in order to prescribe the correct medication. There are five stages of severity of diabetic retinopathy, Mild Non Proliferative Diabetic Retinopathy (NPDR),Moderate NPDR, Severe NPDR, Proliferative Diabetic Retinopathy(PDR) and No DR(Diabetic Retinopathy).This paper summarizes DR detection methods and problems.