The ability of human beings to suppress or inhibit a part of the binocular visual field in strabismus, and only that part of the visual field which is confusing to visual orientation, is a remarkably subtle property. It is a wellknown fact that patients may have full binocular fusion in one position of gaze but, because of extraocular muscle noncomitancy, such as an overactive inferior oblique, may suppress a part of the binocular field in another position of gaze. The suppression is called upon only when needed. In concomitant strabismus, the region of suppression may be shown to have a border at the vertical decussation line through the macula (hemiretinal), which is its most constant, interesting, and clinically useful characteristic.
It is the purpose of this paper to emphasize the clinical advantage of simplicity in testing procedures in the determination of the characteristics of suppression in strabismic patients, to outline