I. There are three most common strabismus: 1) exotropia; 2) internal strabismus; 3) superior oblique muscle paralysis. The folk saying corresponds to teasing chicken eyes, window pushing eyes, and crooked neck. Some exotropia occurs at birth. Most are genetically related. Characteristically, exotropia is large and uncontrollable. Alternating gaze’s. Many of the exotropias that occur later are called intermittent exotropias, which are often associated with myopia without glasses and poor fusion control. The intermittent exotropia will develop into constant exotropia due to the destruction of binocular vision and the increase in the amount of strabismus. Treatment methods: 1. surgery; 2. functional training. For strabismus with a large amount of strabismus or constant exopthalmia surgery is necessary. Smaller amounts of interocular can be trained. Internal strabismus has a congenital, called congenital internal strabismus. Internal strabismus that occurs later is often associated with high hyperopia. A sudden onset of internal strabismus is called acute common internal strabismus. Congenital internal strabismus can cause strabismic amblyopia, even eccentric gaze, and incurable permanent low vision. Therefore, congenital internal obliquity should be taken seriously. Most people with a crooked head may have an eye problem, and congenital superior oblique palsy is more common. Therefore, crooked-headed children seek timely medical attention. Early correction can prevent the imbalance of facial muscle development caused by the crooked head.