The initial stage of diabetic retinopathy may be asymptomatic, followed by a mild loss of vision, and as the disease progresses, vision may become significantly blurred until complete blindness. Some patients may become blind suddenly, mainly because of vitreous hemorrhage; some patients may also experience eye pain and swelling at the same time as they become blind, which may be secondary to glaucoma. Why do these symptoms occur in diabetes? Diabetic retinopathy can be divided into simple and proliferative retinopathy. In the simple stage, microangiomas, hard exudates and cotton wool spots and hemorrhages can occur. When only microangiomas are present, there is no visual impairment, but when hard exudates and flocculent spots occur, vision is affected. Proliferative retinopathy occurs when neovascularization occurs in the retina. Because the walls of the neovascularization are very fragile, it is very easy for vitreous hemorrhage to occur and further retinal detachment to occur, so patients may experience a sudden and significant loss of vision. Neovascularization can also lead to secondary glaucoma, which causes eye pain, eye swelling, and eventually blindness. How to prevent and treat diabetic retinopathy? Once a patient is diagnosed with diabetes, he or she should have regular eye examinations. When the naked or corrected vision is normal, the fundus can be examined once every six months. When there is visual impairment, examination and treatment should be carried out under the guidance of a doctor. 1.First of all, we should control blood sugar well, not to make blood sugar high and low, and should use blood sugar lowering drugs correctly under the guidance of endocrinologist. 2.When the patient has no visual impairment or mild vision loss, take drugs to improve retinal blood circulation, such as Guoxin, pancreatic kinase releasing enzyme, etc. under the guidance of ophthalmologist. 3.When cotton wool-like spots appear in the fundus or neovascularization has been found, then fundus laser treatment should be performed. The purpose of laser treatment is mainly to prevent the further development of retinopathy in order to maintain the existing useful vision of the patient and reduce the blindness rate of diabetic retinopathy. 4. When vitreous hemorrhage is present, conservative treatment with drugs such as Antoine iodine and Tripterygium can be used first; for those who have accumulated blood that cannot be absorbed continuously, vitreous excision surgery is feasible and vision is expected to be improved.