Monofixation syndrome (microtropia or microstrabismus) is an eye condition defined by less-than-perfect binocular vision. It is defined by a small angle deviation with suppression of the deviated eye and binocular peripheral fusion. A rare condition, microtropia is estimated to affect only 1% of the general population. There are three distinguishable forms of this condition: primary constant, primary decompensating, and consecutive microtropia. It is believed that primary microtropia is a result of a primary sensorial defect, predisposing to anomalous retinal correspondence. Monofixation syndrome is a frequent outcome of surgical treatment of congenital esotropia.