High blood sugar affects all organs of the body. Many people go to the hospital after they have lost their sight and learn that they have diabetes. Diabetes is now one of the leading factors in causing blindness. The effects of diabetes on the eye are not just blindness, but can cause damage to every structure of the eye. As an example, diabetics are prone to mydriasis (the effect on the eyelids) and to cataracts (the effect on the lens). Diabetic cataracts. Someone’s lens goes completely white overnight. This is a cataract associated with diabetes, a complicating cataract. But it predicts poorly controlled diabetes. If you compare the eye to a camera, the onset of cataract is when the lens turns from translucent glass partially or completely to gross glass. The lens is normally clear, and light can pass through it to the back of the eye, allowing a clear image to be seen. If the lens becomes partially cloudy and opaque, light will not be able to pass through the cloudy patches. The patches often become larger and increase in size over time. As less light passes through the lens, vision will become blurred or cloudy. The more cloudy the lens, the more vision will be affected. Cataracts are known to be associated with the following factors: 1. Hypertension: The risk of cataracts is two times higher in people with a systolic blood pressure (high pressure) of 160 mmHg than in people with a systolic blood pressure of 120 mmHg. 2. 2, high blood sugar. Some people can even develop cataracts overnight. Diabetic people are prone to cataracts, which we call diabetic cataracts. If blood sugar is not well controlled, cataracts develop quickly, and at the same time, most of those who have diabetes are elderly people, and the combination of two kinds of cataracts is a very troublesome thing. Moreover, if a diabetic patient has a cataract, if he wants to treat his fundus, he cannot treat his fundus because the cataract is blocked in front and he cannot see the fundus at all. Got to give diabetic patients to do crystal replacement surgery for cataracts and do a good job of controlling infection, because diabetics are prone to infection. 3, drugs: some immune disease patients long-term systemic or local application of high-dose glucocorticoids; people with gout take anti-hyperuric acid preparations, etc. 4, long-term outdoor, the eyes receive too much ultraviolet light. 5.Smoking; drinking alcohol. If you have mild cataract, you may not show any symptoms at first. Blurred, cloudy or hazy vision is the most common symptom of age-related cataract. Small spots – opaque patches in the lens – appear when you see things. Vision can be affected by light; for example, you may find it difficult to see in dim or bright light. Cataracts may also make colors look faded or unclear. Perhaps you will find it more difficult than ever to read and watch television. If you wear glasses, you may find that they are not as useful as they used to be. In rare cases, you may see rings of light around bright lights such as car headlights, street lights, etc. Another rare symptom of cataracts is double vision (seeing two images instead of one). If left to progress, acute attacks of closed-angle glaucoma, allergic endophthalmitis of the lens components, lens dissolving glaucoma, and detachment of the lens nucleus into the vitreous may occur at various times in the development of cataract. Eventually blindness results. Having a cataract is like having a dirty lens, we can wipe it and it will be clear again, but what if the negative is broken (the retina is faulty)? The retina is like the negative of a camera, which is an important tissue structure for the human eye to receive light. Once the retina is damaged, it will lead to a significant loss of vision until blindness. Of all the problems, the most serious damage to vision is, diabetic retinopathy. The retina is richly vascularized and is one of the most vulnerable tissues in the body to the dangers of diabetes. In the earliest stage of diabetic retinopathy, small microvascular tumors first appear on the patient’s retina, followed by a decrease in capillary barrier function. Plasma components in the blood leak through the capillary walls and into the retinal tissue, resulting in retinal tissue edema, and the fundus shows the appearance of hard exudate. As the lesion continues to develop, retinal capillary atresia occurs, and ischemic damage occurs in the retinal tissue. When the retinal capillary atresia reaches a certain level, the retina starts to compensate for the growth of neovascularization. As the retinal neovascularization is very delicate, the neovascularization can rupture and bleed during human movement due to vitreous traction. A small amount of bleeding can be confined to the retinal surface, while a large amount of bleeding can fill the eye cavity, at which time the patient’s vision will be significantly reduced. Diabetic retinopathy can be asymptomatic at the earliest stage, but when retinal hemorrhage, exudation and macular edema occur, it can manifest as flashing sensation and vision loss. If the hemorrhage reaches the cavity of the eye, it may manifest as a large black shadow in front of the eyes and severe loss of vision. After the occurrence of traction retinal detachment, as the scope of retinal detachment increases, the vision loss becomes more and more severe until the vision is lost. If the lesion occurs in the macular area, there will be distortion and obscuration in seeing. A self-assessment can be done using the Amsler square chart. Cover one eye and look at this square table. If there are black shadows and straight lines with distortion, it is recommended to seek medical attention.