At present, China has become the world’s number one country for diabetes. According to the latest survey of the Chinese Diabetes Association, the prevalence of diabetes in China is as high as 9.7%, and the number of diabetics in the country is close to 100 million, and China has become the fastest growing region for diabetes in the world. As people’s living standards improve, medical conditions improve, and people live longer, the complications of diabetes are increasing. Twenty years after the onset of diabetes, almost all patients have eye complications. The ocular complications of diabetes are: 1. Conjunctiva: visible bulbar conjunctival veins are twisted, dilated and capillaries are spiral, which easily cause subconjunctival hemorrhage. 2, cornea: hypoesthesia of the cornea, related to the level of blood sugar and disease urine sugar in diabetic patients. 3, iris: very small neovascularization can be seen at the pupil margin, making the iris red. If the neovascularization involves the atrial angle and affects atrial aqueous drainage, neovascular glaucoma can occur, causing headache and vision loss; glycogen deposition on the iris pigment epithelium, pupillary sphincter and open muscle, resulting in blunted pupillary reflex to light and difficulty in pupil dilation. 4. Lens: Hyperglycemia causes swelling and degeneration of lens fibers, leading to clouding under the posterior capsule of both eyes, complicating cataract, blurred vision and monocular diplopia. In young adults with severe diabetes, complicating cataracts can occur at the age of 15 to 20; the maturation time of senile cataracts in the elderly with diabetes is shorter than normal, and the age of onset is younger, while related to the course of diabetes. 5. Retina: The occurrence and development of diabetic retinopathy is related to the degree of glycemic control after the onset of diabetes, age of onset, duration of disease, and genetic factors, and has little relationship with gender and type of disease urinary disease. According to an epidemiological survey, the incidence of diabetic retinopathy is 28% in those with diabetes for less than 5 years, 36.4% in those with diabetes for 6-10 years, 58% in those with diabetes for 11-15 years, and 72% in those with diabetes for more than 15 years. Microangiomas, deep hemorrhages, hard exudates or cotton wool spots are seen on the retina in the early stage of the lesion, and there is a significant loss of vision when there is macular edema. Diabetic retinopathy is divided into background type and proliferative type. In the background type, there are microvascular tumors, hemorrhages and exudates on the retina; in the proliferative type, in addition to microvascular tumors, hemorrhages and exudates on the retina, there are also neovascularization, or vitreous hemorrhages and fibrous hyperplasia, and in severe cases, retinal detachment may cause blindness. 6, eye nerve: extraocular muscle paralysis often occurs suddenly, ptosis, extraocular muscle paralysis, can be bilateral symmetry, or only seen unilaterally, appear blurred vision, double vision; can also occur ischemic optic neuropathy and optic nerve atrophy, affecting visual acuity. 7. Refractive error: Increased blood sugar can cause a decrease in atrial water osmolarity, which can infiltrate into the crystal and make the crystal expand and myopia occur. When blood glucose decreases, the atrial water osmolarity rises, causing the crystal water to seep out and dehydrate, resulting in farsightedness. With the change of blood glucose, patients will appear sometimes to see near clearly and sometimes to see in the eye far clearly. If there is a recent change of refractive status, then the hospital should be due to check whether there is diabetic cataract. In conclusion, diabetes is a systemic disease and also has many eye complications. Some diabetic patients with symptoms of polyphagia, polyphagia, polyuria, and weight loss are not obvious, and even the first time they are seen for eye complications. For those who have recurrent wheals on the eyelids, double vision in both eyes, and sometimes good and bad vision, or sudden vision loss, they should be seen promptly and have their blood sugar checked to prevent misdiagnosis. Patients with diabetes should also be aware of regular eye examinations.