Exotropia differs from esotropia not only in direction and size of the deviation but also with respect to prevalence, sex predilection, age of the patient at onset, progression of the disease, prognosis, nature of the underlying sensorial adaptation, and the etiologic significance of associated refractive errors. Also, exodeviations are much more common in a latent or intermittent form than are esodeviations. A patient may exhibit a manifest exotropia during one examination, and at another time an exophoria or intermittent exotropia. Indeed, it is common to observe rapid switching from one phase to the other during the same examination.

Mechanisms responsible for these variations include the degree of fusional control with varying levels of alertness, the convergence accommodation relationship, and the change of the angle of deviation at different fixation distances.

Therapy is not required for patients who have exophoria without muscular asthenopia.