title: Visual detection and adaptation to optically induced curvature distortion. Does curvature distortion govern progressive addition lens tolerance?
abstract: We attempt to test the hypothesis that patients who fail to tolerate spectacle lenses may do so as a result of their inability to adapt to the induced curvature distortion. Detection of an adaptation to optically induced curvature distortion occurs to a variable extent among a subject population [I. Rock, The Nature of Perceptual Adaptation (Basic Books, New York, 1966)]. Some patients find progressive addition spectacle lenses (PAL's), which are used for the correction of presbyopia, a difficult type of lens to wear, possibly because of the peripheral distortion shown by the lens. [Ophthal. Physiol. Opt. 9, 163 (1989)]. Two presbyopic subject samples (N = 20) of those who successfully adapted and those who failed to adapt to PAL's are presented, and the variation in the detection of and the adaptation to optically induced distortion of a single line are studied with Gibson's wedge prism approach (J. Exp. Psychol. 16, 1 (1933)]. A third sample (N = 20) of prepresbyopes is included as a control group. This study shows that the detection of and the adaptation to optically induced curvature distortion, as assessed with monocular vision, does not govern patient tolerance. Significant age-related differences in the rate of adaptation are noted between presbyopes and prepresbyopes.
authors.forename: C M
authors.initials: CM
authors.lastname: Sullivan
authors.forename: C W
authors.initials: CW
authors.lastname: Fowler