Varied Human Tolerance to the Combined Conditions of Low Contrast and Diminished Luminance: A Quasi-Meta Analysis

Abstract : Human physiological tolerance to performance-based stressors or obstacles is an important issue common to every cellular and neurologic bodily system. Visual performance assessments are on a sliding scale, subject to known determinate factors, which control the final level of actual performance. There logically are also a number of unknown determinants or controlling factors that must be understood, as well. Over the years a host of visual performance studies have separately evaluated the effects of varied illuminance on acuity, as well as the effects of varied target contrast on acuity. However, few have looked at the combined challenge of altered contrast, while subject to decreased retinal illuminance. It wasnt until approximately 2002, when a great many refractive surgery post-operative evaluations began assessing visual performance under varied luminance and contrast levels. This research effort will review any and all studies on visual performance under either, or both of these two conditional variables (i.e., decreased target contrast in conjunction with conditions of decreased luminance, as well as each individual condition).