VISUAL DETECTION AND ADAPTATION TO OPTICALLY INDUCED CURVATURE DISTORTION - DOES CURVATURE DISTORTION GOVERN PROGRESSIVE ADDITION LENS TOLERANCE

We attempt to test the hypothesis that patients who fail to tolerate s pectacle lenses may do so as a result of their inability to adapt to t he induced curvature distortion. Detection of an adaptation to optical ly induced curvature distortion occurs to a variable extent among a su bject population [I. Rock, The Nature of Perceptual Adaptation (Basic Books, New York, 1966)]. Some patients find progressive addition spect acle lenses (PAL's), which are used for the correction of presbyopia, a difficult type of lens to wear, possibly because of the peripheral d istortion shown by the lens. [Ophthal. Physiol. Opt. 9, 163 (1989)]. T wo presbyopic subject samples (N = 20) of those who successfully adapt ed and those who failed to adapt to PAL's are presented, and the varia tion in the detection of and the adaptation to optically induced disto rtion of a single line are studied with Gibson's wedge prism approach [J. Exp. Psychol. 16, 1 (1933)]. A third sample (N = 20) of prepresbyo pes is included as a control group. This study shows that the detectio n of and the adaptation to optically induced curvature distortion, as assessed with monocular vision, does not govern patient tolerance. Sig nificant age-related differences in the rate of adaptation are noted b etween presbyopes and prepresbyopes.