Children in early childhood generally do not express symptoms of vision loss, often manifesting as diligent blinking, squinting, or head tilting. Therefore, the best time to treat astigmatism is as soon as parents discover or detect astigmatism in their children. The critical period for children’s visual development is from 0 to 3 years old, and the sensitive period is before 6 years old, and is generally fully developed by 12 years old. Astigmatism not only affects visual acuity and causes visual fatigue, but also affects visual development during the child’s development, resulting in amblyopia and strabismus. Therefore, parents must correct astigmatism in a timely manner if they find it in their child’s eyes. before the age of 3, because the visual function of both eyes is not yet fully developed, adverse visual factors can easily lead to amblyopia and affect the formation of visual function of both eyes. After the age of 3, the visual function of both eyes is established but not yet perfected, and timely correction can make the monocular function of both eyes established and developed to a certain extent, but the treatment effect is weaker than before the age of 3. Therefore, before the age of 3 is the critical period of visual development, and before the age of 12 will have certain effect. Astigmatism should be treated in time after it is found, and at this time there is great plasticity in visual development, and the younger the age, the greater the plasticity.