Suprathreshold Contrast Sensitivity Vision Test Chart.

Although visual acuity has been the main measure of visual capability for over 125 years for both the military and civilians, it has been shown not to relate well to visual performance. A new measure of visual capability, contrast sensitivity, has been shown to relate to individual differences in visual capability such as target detection in the laboratory in flight simulators and in field studies. Contrast sensitivity testing with sine-wave gratings provides a very accurate measure of target detection threshold. However, although threshold measurements are very important in evaluating pilot visual performance, there are many other critical visual tasks performed at suprathreshold contrast levels. Rountine measurement of suprathreshold contrast sensitivity has been difficult to accomplish until now, however, due to the expensive, time-consuming, and complex computer-video systems required for testing. To answer this need, Vistech Consultants, Inc. proposed to develop a new suprathreshold contrast sensitivity vision test chart. This chart was to be designed to measure individual differences relate to visual performance. The psychophysical procedure of contrast matching was used to measure an individuals suprathreshold contrast perception of sine-wave gratings for appropriate ranges of spatial frequency and contrast.