Vision multiplexing in the design of low vision devices

Abstract

The normal visual system provides us with a very wide field of view at an apparent high resolution. The wide field of view is continuously monitored at a low-resolution providing information for navigation and detection of objects of interest. These objects of interest are sampled over time using the high-resolution fovea applying a temporal multiplexing scheme. Most disabling low-vision conditions impact upon only one of the components, the peripheral low-resolution wide field or the central high-resolution fovea. The loss of one of these components prevents the interplay of central and peripheral vision needed for normal function and causes disability. Traditional low vision aids improve the impacted function, but usually at a cost of a significant loss in the surviving function. For example, magnifying devices increase resolution but reduce the field-of-view, while minifying devices increase the field-of-view but reduce resolution. A general engineering approach — vision multiplexing — that takes advantage of the dynamic nature of human vision is presented. Vision multiplexing seeks to provide both the wide field of view and the high-resolution information in ways that could be accessed and interpreted by the visual system. The use of optical methods and computer technologies in the development of a number of new visual aids, all of which apply vision multiplexing to restore the interplay of central and peripheral vision using eye movements in a natural way. Recent developments in a number of multiplexing will be described.