OPTIMIZING THE VISIBILITY OF DISPLAYS FOR OLDER OBSERVERS

Aging is associated with a variety of decremental visual changes, including reductions in retinal illuminance, color discrimination, static and dynamic acuity, near focus, contrast sensitivity, smooth and saccadic eye movements, visual field, visual search, and the ability to see in and recover from glare. Laboratory research, field studies, and self-report data all indicate that many older persons experience significant difficulty in carrying out tasks that depend on these visual functions. It is also increasingly clear that older observers' performance in finding, extracting, and using visual information can be enhanced significantly by designing ask environments to minimize the effects of visual deficits. Recent research indicates that optical simulation of visual loss and contrast sensitivity testing, used in conjunction with image processing, may be very powerful tools for designing displays for the elderly and others with diminished spatial vision. These developments are reviewed, and general guidelines for creating ergonomically correct visual task environments for older observers are offered.