The distinction between internal and external strabismus depends on the refractive state of the eye. In the case of internal strabismus, a dilated eye exam should be performed to determine the refractive state, and it is usually more likely that the high number of hyperopia causes internal strabismus. In case of exotropia, there are constant exotropia and intermittent exotropia. If the angle of constant exotropia is large, surgery can be considered directly. If the angle of exotropia is relatively large and frequent, surgery is still recommended; if it is occasional and the angle of exotropia is relatively small, it is also recommended to observe and correct the eyes first to see if it can be controlled, and if it cannot be controlled, surgery is still an option.