Gerald Westheimer, OD, PhD
Clinical Professor Emeritus of Optometry
Professor of Neurobiology
Monday, February 1, 2021
11:10 am - 12:30 pm
The Optical Image on the Retina
Whether in the Eye Clinic or the Vision Science Laboratory, the optical image on the retina is the nexus between what is shown and what is seen. Long the province of geometrical optics and diffraction theory, and the subject of measuring and computing, it has recently gained renewed relevance in two areas.
Advances in reshaping, substituting and supplementing the eye’s natural optical components, and developments in optical and material technology, have opened new vistas in customizing the eye’s refracting state. Several examples will be given of sophisticated modifications of the eye’s optical apparatus, whose design and testing involves knowledge of the properties of the retinal image.
A challenge to traditional thinking in this area has been the discovery of axial length changes when the beam intercepted by the retina is defocused, and differentially so depending on whether the defocus is hyperopic or myopic. The possible implication for the etiology of myopia cannot be overlooked. Accordingly, a detailed analysis of how the defocus polarities might be distinguished will be presented, in terms of diffraction theory, chromatic aberration, the Stiles-Crawford effect and the spectral sensitivities of presumed detecting mechanisms in the fundus.