While most people can look at the same object with both eyes, a minority of people cannot look at the target with both eyes at the same time, which is called strabismus. As a common ophthalmic condition, strabismus affects the patient’s visual acuity, the development of visual function in both eyes, and the aesthetics. The most common types of strabismus are congenital internal strabismus according to the age of onset, common strabismus and non-common strabismus according to the strabismus pattern, as well as regulatory and non-regulatory strabismus according to the regulatory supply, intermittent and constant exotropia and constant exotropia according to the frequency of onset, and some special types of strabismus. The clinical manifestations of different types of strabismus are different. Congenital internal strabismus usually develops within the first 6 months of life and is usually not combined with obvious refractive abnormalities, and there is no amblyopia if the strabismus occurs alternately in both eyes. Monocular strabismus can be combined with amblyopia. If the strabismus is large and pseudo-extension is limited, it can be combined with hypermetropia and nystagmus. Common internal strabismus may be associated with refractive error, combined or uncomplicated amblyopia. There is no significant restriction of eye movements there is some binocularity or near looking internal strabismus. Patients with intermittent exotropia have a tendency to squint in bright light and control function in the orthotropic position, and when the eye position is deviated, the deviated eye can have suppression, so there is often no diplopia. In constant exotropia, the eye position is often alternately deviated, and suppression may be present in those who develop eye position deviation before the age of 5. After the age of 5, diplopia may be present, and children may also have compensatory head position and body position. As can be seen, the nature of strabismus and the time of its development determine its symptoms, and the condition of performance varies from condition to condition.