Binocular foveation in reading.

We present a theory of foveation in normal binocular reading. We consider the pervasive, nontrivial binocular fixation disparities (FDs) observed in reading and relate them to the computational problem of resolving retinal disparities in depth perception. We infer that the right eye's fixation being to the right of the left eye's in reading promotes binocular fusion in challenging conditions. We then show a different (nonfusional) processing advantage for the right eye's fixation being to the left of the left eye's in reading conditions in which binocular fusion is assured, by modeling the combined influence of foveal splitting, contralateral preference, ocular prevalence, and fixation disparity. This synthesis of anatomically grounded research in different aspects of visual processing produces a theory of foveation in reading that matches current data and makes testable predictions.