A 10-year-old child with 4.8 vision in one eye belongs to vision loss, but not necessarily myopia, because myopia, hyperopia, amblyopia, astigmatism and so on can cause children’s vision loss, and it needs an optometry examination to determine whether the child suffers from myopia. A 10-year-old child with a visual acuity of 4.8 in one eye can be given a dilated optometry examination in time to determine whether the child’s refractive state is normal and whether he or she is suffering from myopia. If the optometry examination reveals that the child is suffering from myopia, the child needs to wear eyeglasses in time to correct the myopia so as to improve the visual acuity. In order to avoid myopia progression and development of high myopia, children need to maintain good eye habits, maintain good sitting posture, avoid lying on the table to write homework, do not allow children to study in dimly lit environments, and look at fewer cell phones, computers and other electronic products. If the optometry examination is normal and refractive error is ruled out, the child should also undergo funduscopic examination and slit lamp examination to find out the cause of vision loss. It is recommended that children with vision loss should be seen in a hospital in time to have their condition evaluated and treated according to the doctor’s instructions.