In our clinical work, we often encounter parents of children with strabismus who anxiously ask when is the best time to have surgery. For children with strabismus, our pediatric ophthalmologists are most concerned about the child’s binocular vision development. 6 years old is the critical period for binocular vision development, and strabismus that occurs during this period should be treated as early as possible if it has an impact on binocular vision development. For each child with strabismus, the type of strabismus, the presence of amblyopia, and the age of onset will affect the timing of surgery. For congenital strabismus occurring within the first 6 months of life, children with early onset of strabismus do not have the conditions for the establishment of binocular vision because of the presence of strabismus and have poor binocular vision, so early surgery is recommended, and the age of surgery should not be older than 2 years. Due to the use of adjusted suture strabismus correction, the youngest child treated surgically in our department is currently 8 months old. In children with congenital paralytic strabismus, strabismus occurs because certain muscles that govern eye movements are paralyzed and weakened. In order to eliminate the diplopia caused by strabismus, the child often develops a compensatory head position, turning the head and face in the direction of the action of the paralyzed muscles. Over time, the development of the face on the side of the head position is affected and becomes smaller, which seriously affects the facial aesthetics. Once the facial asymmetry occurs, the strabismus cannot be restored even if it is cured surgically. Therefore, when the diagnosis of congenital paralytic strabismus and eye movement examination are clear, early surgery can be performed to improve the head position. The youngest child treated in our department is 5 months old. Acquired common strabismus is one of the major categories of childhood strabismus. Some of these children with moderate internal strabismus have refractive abnormalities, are amblyopic, and are unable to establish binocular vision because of the presence of strabismus. The general principle is that surgery should be performed when amblyopia is cured or visual balance is achieved, and surgery should be performed before the age of 6 years as far as possible; relatively few children with intermittent exotropia have amblyopia, because most of them have binocular vision because of their acquired appearance. The general principle is to follow up regularly in the outpatient clinic to observe whether the strabismus is aggravated and the visual condition of both eyes, and if partial loss of the original visual function of both eyes is found, surgery is the treatment of choice. In children with acquired paralytic strabismus, if the cause is clear, neuropharmacological treatment is first applied. After 3-6 months of onset of the disease, the strabismus degree is stable before surgical treatment can be performed.