A 9-year-old child with 4.7 visual acuity needs to go to the eye hospital for examination. If it is caused by refractive error, glasses can be worn to correct the vision, otherwise wearing glasses is useless. Usually, children around 7-8 years old have fully developed vision and can achieve normal vision of about 5.0. 4.7 vision in a 9-year-old child indicates that the child has vision loss, if it is clearly caused by myopia through optometry. The child can wear glasses to correct the myopia and improve the vision. However, if the vision loss is caused by cataract, glaucoma, retinal detachment, etc., rather than refractive error, the child does not need to wear glasses, as they are not useful. Children can be treated with medication or surgery as prescribed by the doctor to improve their vision. Children should also pay attention to moderate eye use, avoid prolonged use of cell phones, computers, etc., so that the eyes can get enough rest to avoid further vision loss. Children with vision loss are advised to consult a doctor to evaluate their condition and follow the doctor’s instructions.