Visual acuity has been the mainstay of military vision standards since 1913. Since then, however, visual acuity has been shown not to relate well to visual performance. Recently, contrast sensitivity using sine-wave gratings has been shown in the laboratory, in flight simulators, and in field studies to relate to individual differences in visual target detection capabilities. Although target detection thresholds are an important aspect of pilot visual performance, many visual tasks important to military considerations are performed at suprathreshold contrast levels. We propose that a new vision test chart be developed to measure individual differences in suprathreshold contrast perception, and to show how they relate to pilot performance. This suprathreshold contrast sensitivity test system will use the psychophysical procedure of contrast matching to measure an individual's suprathreshold contrast perception of sine-wave gratings for appropriate ranges of spatial frequency and contrast. The resulting data will provide an array of curves from just-above threshold to high suprathreshold, thereby establishing a range of individual suprathreshold visual capabilities. These curves will be similar to the loudness sensitivity curves in audition. Follow-up research will use these vision test charts to relate individual differences in suprathreshold contrast sensitivity to air force-related performance tasks.
