Whether or not a 6-year-old child with a vision of 0.4 can be corrected is related to the cause of the child’s low vision; if it is caused by myopia it can be corrected, but if the vision loss is caused by glaucoma, retinopathy, etc., it is usually more difficult to correct. The vision level of a 6-year-old child is around 0.8-1.0. If the child has only 0.4, the child’s vision is lower than that of his or her peers. If the child’s vision loss is caused by refractive errors such as myopia or astigmatism, the patient may be able to correct the refractive errors and improve vision by wearing glasses or refractive surgery. If the child’s low vision is caused by fundus conditions such as retinopathy of prematurity, congenital macular degeneration or congenital glaucoma, it is often difficult to correct. It is recommended that patients with low vision seek prompt medical attention to assess their condition and choose the appropriate treatment under the guidance of their doctor.