Sudden blurring of the eyes after running may be caused by hypoglycemia, retinal detachment, and central retinal artery embolism. 1. Hypoglycemia: Eating less before running, running for too long, running with too much intensity and so on. The body consumes too much, which leads to hypoglycemia after running and blurred vision. 2. Retinal detachment: If the patient is medium or high myopia, when the eyes are stimulated during strenuous exercise, there are cracks and detachment of the retina. Symptoms such as sudden blurring of the eyes and dark shadows fluttering in front of the eyes may occur. 3. Embolism of central retinal artery: If the patient has hypertension, hyperlipidemia, atherosclerosis and other underlying diseases, the embolus may fall off and block the central retinal artery when running, causing a sudden and drastic decrease in vision and sudden blurring of the eyes. Sudden blurring of vision in the eyes, it is recommended to consult a doctor in time, follow the doctor’s instructions for further examination, clarify the cause with the help of the doctor, and carry out targeted treatment or therapy.