In general, a 13-year-old child with a visual acuity of 4.6 is not normal. Naked eye visual acuity refers to the visual acuity of the eyes obtained by visual acuity chart examination, general visual acuity is divided into distance and near vision, normal visual acuity is usually above 5.0. 13-year-old child visual acuity of 4.6, indicating that the visual acuity is lower than the normal value, leading to lower vision for a number of reasons, the common causes of refractive errors such as nearsightedness, farsightedness, astigmatism and other refractive errors. In addition to refractive errors, causes of vision loss include ophthalmic diseases, and if this is the cause, the primary disease needs to be treated. The child has a visual acuity of 4.6 at the age of 13. He needs to go to the ophthalmology department of the hospital for appropriate optometry to clarify the cause of the disease, and then treatment and correction will be carried out to address the cause of the disease.