Fixation disparity in relation to heterophoria.

The phenomenon of fixation disparity is of interest in the study of fusional processes in patients with single binocular vision. An understanding of its mechanism is of im­ portance in the pathogenesis of strabismus. The clinical determination of the amount and type of fixation disparity relative to its practical clinical and therapeutic implications has been discussed elsewhere. The present study describes a laboratory determination of the type and amount of fixation disparity existing under approximately natural visual conditions.