High blood sugar leads to blurred vision in two general cases: 1, patients with significantly higher blood sugar will lead to changes in the refractive power of the eye lens, resulting in blurred vision, blood sugar control will gradually improve, generally do not need to do special treatment for blurred vision; 2, diabetic patients with a long history of poor blood sugar control, will also have blurred vision, when the fundus examination is performed suggesting the presence of fundus hemorrhage. If diabetic retinopathy occurs, it is often irreversible damage and can be treated with laser therapy, as well as treatment to improve microcirculation in the eye, mainly to control diabetic retinopathy from continuing to progress forward and cause blindness in patients, but not to the extent of a cure.