Diabetes can cause a variety of eye diseases, such as glaucoma, vitreous hemorrhage, optic neuropathy, and most commonly retinopathy and cataracts. Since the visual impairment caused by diabetic eye disease is often irreversible, the earlier the treatment, the better the outcome. It is more important to prevent the occurrence of diabetic eye disease than to treat it. The following points should be noted to prevent the occurrence of diabetic eye disease: strict control of blood sugar is the fundamental measure to prevent the development of diabetic eye disease. Some experts have carried out more than 20 years of observation, found that more than 80% of diabetic patients with poor blood sugar control, after 20 years will develop retinopathy, and good control of diabetic patients, only about 10% of retinopathy, the difference is very big. Also blood pressure and blood lipids are important in preventing the development of diabetic retinopathy. Two groups of diabetic patients, one with hypertension and one with normotension, were studied to observe the effect of blood pressure on diabetic retinopathy, and the results showed that the incidence of diabetic retinopathy in the hypertensive group was 34% higher than that in the normotensive group. The results indicate that it is important to control blood pressure and that diabetic eye disease can easily develop if blood pressure is not well controlled. The study also found that poor lifestyle, affects the development of diabetic eye disease including diabetic retinopathy. Diabetic patients must quit smoking and alcohol; diet should be light, less spicy, stimulating and high-fat foods; proper exercise, exercise not only helps to lower blood sugar, but also helps to reduce the occurrence of diabetic eye disease; brain workers should pay attention to avoid the visual fatigue caused by long hours of reading and long hours of computer use. Early treatment of diabetic eye disease is often able to obtain better results and enable patients to maintain useful vision. Therefore, patients must consciously ask their doctors to check their vision, fundus and eye conditions at regular eye examinations.