1, early patients do not feel anything, but the doctor can already see through the examination of the patient’s fundus has changed; 2, when there is retinal edema, the patient can appear blurred vision; 3, if the vitreous hemorrhage is more, it obviously affects vision, or even completely missing vision; 4, when the retinal edema waves and macula, the patient can feel the visual distortion; 5, late severe hemorrhagic retinal detachment, often 6. If neovascularization of the iris or atrial angle occurs, neovascular glaucoma symptoms may appear, and there may be uncontrollable eye pain, headache, nausea and vomiting. Although diabetic retinopathy cannot be prevented, the risk factors leading to its occurrence can be reduced by the following methods: 1. regular blood glucose testing 2. regular urine glucose testing 3. fundus examination every 3 months to 6 months 4. strict control of diabetes 5. strict use of hypoglycemic drugs as prescribed by the doctor 6. diet control to control blood glucose levels 7. exercise to lower or help the body consume blood glucose