11-year-old vision 0.4, if refractive error caused by vision loss, need to be corrected with glasses, otherwise you need to treat the original disease first. If your vision is 0.4 at the age of 11, you should first go to the hospital to check if it is caused by refractive error. If it is a refractive error such as farsightedness, astigmatism, myopia, etc., it needs to be corrected by glasses as soon as possible. Otherwise, it may cause further aggravation of the condition and affect the patient’s normal life and study. If the vision loss is caused by other diseases, such as fundus hemorrhage, wearing glasses is of little significance, and you need to go to a professional hospital in time. With the treatment of the original disease, vision can usually be slowly recovered. It is recommended that patients seek timely medical attention to determine the cause of vision loss, and under the guidance of the doctor, correct their vision by wearing glasses and other measures.