The most important cause of blindness in diabetic patients is diabetic retinopathy. The eye is a highly concentrated part of the human nervous system and vascular system, and once the blood sugar rises, it will have certain effects on the body tissues, especially the damage to the optic nerve system, leading to the occurrence of diabetic eye disease, causing patients to have dry eyes, vision loss, blurred vision and black shadows in front of the eyes and other symptoms, and too long may This can lead to blindness. Diabetes, as a chronic disease, does not have specific early manifestations, the most common of which is vision loss. Diabetes can cause a variety of eye complications, such as immune deficiencies that can lead to eye infections and increased eye discharge. Patients with diabetic cataract can manifest as vision loss, blurred vision, feeling of a layer of fog in front of the eyes that cannot be removed after rubbing the eyes, and feeling that sunlight and light are particularly harsh. If the vitreous is cloudy, flying mosquitoes may appear, affecting macular degeneration and optic nerve atrophy, leading to vision loss and affecting the nerves, resulting in drooping eyelids, double vision, dizziness, unstable walking, and even nausea and vomiting. Diabetic retinopathy is of most concern as a major cause of blindness in diabetic patients, with early treatment being effective but mostly asymptomatic. Once there is a significant loss of vision retinopathy is often difficult to reverse, most patients are only found to have retinopathy because of sudden vision loss, red shadow of vision and blindness, so the most important part of prevention is early examination, early detection and early treatment.