We often meet parents who bring their children to the clinic, “My child sometimes likes to look at the TV with a squint, is it strabismus?” “My child is said to have crossed eyes, is it strabismus?” In clinical diagnosis of strabismus, the main method is to use a flashlight to shine at 33cm from the child’s vertical nasal root, and observe the position of the light reflecting point on the cornea, if it is in the center of the cornea, and the child’s eyes do not move when alternately covered and uncovered, it indicates that the child does not have strabismus. Some children look like strabismus but do not have strabismus by corneal reflectance examination. As the child grows older, the nasal bridge grows taller and the canthus disappears, so the child no longer looks strabismic. This type of strabismus is called “intermittent strabismus” and is unstable. When the child is focused, the eye position is correct and there is no strabismus, but when the child is distracted, the eye becomes skewed. The timing of surgery is determined by checking whether the child has binocular synoptic function through the synoptic machine. If the child still has binocular synoptic function and the strabismus has no tendency to worsen, the strabismus can be corrected through binocular synoptic machine training; if binocular synoptic function has been lost, surgery can be done as early as possible and then post-operative training through synoptic function.