Abstract

The human retina discretely samples the visual scene with spatial arrays of sampling elements such as photoreceptors and ganglion cell receptive fields. These sampling operations potentially render the human visual system susceptible to aliasing; if the retinal image changes too rapidly over distances comparable to the spacing between sample points, the visual system can make errors in reconstructing the visual scene. Aliasing can be seen when interference fringes of sufficiently high spatial frequency are imaged on the cone mosaic (reviewed in Williams, in press). Subtle aliasing effects can also be seen when viewing conventional high contrast, high spatial frequency gratings in the periphery (e.g. Smith and Cass, 1987; Thibos, Walsh, and Cheney, 1987; Galvin and Williams, submitted). However, aliasing is remarkably difficult to observe under most normal viewing conditions. Many mechanisms have been suggested as offering the visual system protection against aliasing at various locations across the visual field. This talk will assemble the available evidence in order to weigh the the effectiveness of these proposed mechanisms.

© 1992 Optical Society of America