Contrast sensitivity, acuity, and the perception of 'real-world' targets.
A major assumption underlying the use of contrast sensitivity testing is that it predicts whether a patient has difficulty seeing objects encountered in everyday life. However, there has been no large-scale attempt to examine whether this putative relationship actually exists. We have examined this assumption using a clinic based sample of adults aged 20-77 years. Contrast thresholds were measured for both: (1) gratings of 0.5-22.8 cycles/degree; and (2) real-world targets (faces, road signs, objects). Multiple regression techniques indicated that the best predictors of thresholds for real-world targets were age and middle to low spatial frequencies. Models incorporating these variables accounted for 25-40% of the variance. Although acuity significantly correlated with thresholds for real-world targets, the inclusion of acuity as a predictor variable did not improve the model. These data provide direct evidence that spatial contrast sensitivity can effectively predict how well patients see targets typical of everyday life.
Owsley
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Department of Ophthalmology, School of Medicine, Eye Foundation Hospital, University of Alabama, Birmingham 35294.
Sloane
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D000328:Adult; D000367:Age Factors; D000368:Aged; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology; D012044:Regression Analysis; D012684:Sensory Thresholds / Q000502:physiology; D014792:Visual Acuity