Depending on the type of strabismus, there are various manifestations of strabismus. Strabismus refers to the inability of both eyes to look at the target at the same time and is a disease of the extraocular muscles, which can be divided into two categories: common strabismus and paralytic strabismus. Common strabismus is characterized by no eye movement disorder and the same degree of strabismus in the first eye position (looking straight ahead) and the second eye position (looking up, looking down, looking left, looking right); paralytic strabismus has limited eye movement and diplopia, which can be congenital or caused by trauma or systemic diseases. According to the direction of the abnormal eye position, it is roughly divided into: horizontal strabismus (internal strabismus, external strabismus) and vertical strabismus. (1) Internal strabismus: the eye position is inwardly skewed, usually with moderate to high hyperopia or abnormal accommodation cohesion and accommodation ratio. (2) Exotropia: the eye position is outwardly skewed and is generally classified as intermittent or constant exotropia. Intermittent exotropia exhibits an outwardly slanted eye position only occasionally in sunlight or when fatigued and distracted. Some patients also show that strong sunlight often closes one eye from time to time, and intermittent exotropia often develops into constant exotropia. (3) Vertical strabismus: the eye position is upward or downward skewed, which is less common than internal strabismus and exotropia, and the upward and downward strabismus is often accompanied by skewed head position. Therefore, the main manifestation of strabismus is eye position deviation, in addition to other diverse manifestations.