CONSEQUENCES OF MONOCULAR DIPLOPIA FOR THE CONTRAST SENSITIVITY FUNCTION

Though the human eye generally creates a single image on the retina, t he literature contains many examples showing perceptual monocular dipl opia. Previously, monocular diplopia resulting from astigmatic defocus has been demonstrated to cause a notch (local minimum) in the contras t sensitivity function (CSF). We examine Verhoeff's (1900) model which explains how monocular diplopia can occur through an interaction betw een defocus and common ocular aberrations. From the measured ocular tr ansverse aberration function and from the measured monocular diplopia of three cyclopleged subjects we predicted multiple notches in the CSF with hyperopic spherical defocus, Monochromatic and polychromatic CSF were measured for vertical gratings with best refraction and with sim ulated myopia and hyperopia. Multiple notches in CSF were observed exp erimentally. Notches in the polychromatic CSF were smaller and broader than those found in the monochromatic CSF. Our aberration model was s uccessful in predicting notches in the CSF with hyperopic spherical de focus. The implications for clinical measurement of CSF are discussed. Copyright (C) 1996 Elsevier Science Ltd.