Diabetic patients with long-term high blood sugar can lead to blurred vision. The solution for blurred vision caused by high blood sugar needs to be determined on a case-by-case basis and is divided into the following situations: First, a significant increase in short-term blood sugar can lead to a change in the atrial osmotic pressure of the patient and the symptoms of blurred vision. At this time, as long as the blood sugar is controlled in the normal range, the blurred vision will improve. Second, cataracts, long-term high blood sugar is easy to form metabolic cataracts, resulting in blurred vision. If the blurred vision is caused by cataract, crystal replacement surgery is needed to solve the problem. Third, fundus retinopathy, long-term hyperglycemia can be combined with diabetic retinopathy, resulting in retinal hemorrhage and exudation, which will also lead to blurred vision, and at this time, fundus laser surgery should be performed to treat it. Fourth, due to high blood sugar in diabetic patients, macular degeneration and refractive error may also occur, resulting in blurred vision.