Blurred vision is one of the most commonly seen complication symptoms in diabetic patients. There are various causes of blurred vision, such as diabetic retinopathy, cataract, vitreous opacity, glaucoma, etc., which need to be differentiated. The most common of these is diabetic retinopathy. Diabetic retinopathy is one of the most important eye diseases leading to blindness, and the occurrence and development of diabetic retinopathy is mainly related to two factors: the level of blood sugar control and the duration of diabetes, which can cause damage to the retinal microvasculature and optic nerve over time. The risk of retinopathy in patients with type 2 diabetes for 15 years or more is 78%, of which about 1/3 have macular edema and 1/6 have proliferative lesions. The pathogenesis of diabetic retinopathy is not fully understood, but it is generally believed that the disease is due to damage to the retinal microvascular system. It is mainly related to the disorder of glucose metabolism. When the blood glucose exceeds the normal level (HbAlC>6.2%), there is no blood glucose Kan value for the occurrence of various complications, that is, the degree of hyperglycemia is delayed correlation with the risk of complications, and microvascular complications can occur as long as the blood glucose rises, and the disorder of glucose metabolism is the root cause of diabetic retinopathy. Second, altered blood viscosity, microvascular endothelial damage, and luminal occlusion predispose to microthrombosis and aggravate retinopathy. In addition, the disease is related to hemodynamics, oxidative stress, cytokines, and genetic factors. Staging of diabetic retinopathy Diabetic retinopathy is divided into “non-proliferative retinopathy” and “proliferative retinopathy”. “Non-proliferative retinopathy” is divided into three stages: mild, moderate and severe, which can be reversed and recovered with good control; at the stage of “proliferative retinopathy”, it is not only difficult to recover, but also not easy to control its development. Diagnosis of diabetic retinopathy Diabetic retinopathy is a manifestation of diabetic microangiopathy, with characteristic fundus changes such as microangiomas and neovascularization. Anatomically, the retina is located at the base of the eye, and with conventional examination methods, the retina cannot be observed. Therefore, the application of fundus fluorescence angiography is needed to dynamically visualize retinal microcirculation and vascular lesions. Treatment of diabetic retinopathy First, strict control of blood glucose and blood pressure is required to reduce the fluctuation of blood glucose and blood pressure and keep them stable within the normal range for a long time, so that the progression of diabetic retinopathy can be delayed. If hyperglycemia and hypertension are not strictly controlled, severe retinopathy can occur even if the patient has a short course of disease. In contrast, those with well-controlled blood glucose and blood pressure not only have a low incidence of retinopathy, but also have a relatively mild degree of it. Secondly, it is necessary to reduce blood lipids and blood viscosity, improve microcirculation, and prevent thrombosis. Commonly used drugs include aspirin, calcium hydroxybenzenesulfonate, pancreatic kininogenase and so on. In addition, some Chinese herbal medicines with the function of activating blood circulation and resolving stasis also have better efficacy in promoting the absorption of blood clots in the fundus, commonly used drugs include Thirty-six Flavored Anti-thirst Capsules, Compound Dan Shen Drops, and Blood Brightening Tablets, Compound Thrombosis Tablets, and Astragalus Granules. Third, laser and surgical treatment. Drug treatment is mainly used for non-proliferative retinopathy, and for proliferative retinopathy, laser treatment can be used. For each affected eye, at least 4 to 5 laser sessions are required to complete the course of total retinal photocoagulation. The laser can coagulate hemorrhage sites, close neovascularization, reduce retinal edema and oxygen consumption, protect central vision, and reduce the chance of retinal and vitreous hemorrhage. Although laser treatment cannot cure diabetic retinopathy, it can play a role in delaying the progression of retinopathy, protecting residual vision, and preventing blindness. Patients with severe diabetic retinopathy who do not undergo laser total retinal photocoagulation will eventually go blind. Fourth, if the lesion is too severe to be treated with retinal photocoagulation, if there is a lot of bleeding in the fundus, or if a proliferative membrane is formed in front of the retina and the retina is detached, surgery is needed as soon as possible to remove the cloudy vitreous with special surgical instruments, peel off the proliferative membrane, and reset the retina. When diabetic patients develop retinopathy, they must strictly control their blood sugar to reach the standard, and on this basis, treat the symptoms.