Computerized Arden grating technique for the measurement of the contrast sensitivity function.
We developed a computerized contrast sensitivity function (CSF) measurement technique using a computer graphics board to reproduce Arden grating type stimuli. The reliability of the procedure was examined by evaluating the standard deviation of repeated test differences. The validity of the procedure was tested by comparison with both a manual method of adjustment technique and with Regan low contrast letter charts. The procedure has been performed at a number of exposure speeds to account for the effect of reaction time and attention of the results. The optimum exposure time for the procedure has been found to be greater than or equal to 22 s. As a result of the benefits of automation the test is quick, produces test-retest correlation coefficients for the five spatial frequencies tested which are similar to those for the method of adjustment procedure (0.76 to 0.91 for the computerized test, 0.66 to 0.88 for the signal generator measurements), and produces values which correspond closely with the method of adjustment measurement. It has the advantages of utilizing hardware already available in many computer systems, having a constant mean luminance across the screen, and having a constant and optimized presentation time.
Cox
M J
MJ
Department of Optometry and Vision Sciences, University of Manchester Institute of Science and Technology, United Kingdom.
Wood
I C
IC
D000328:Adult; D003196:Computer Graphics; D015350:Contrast Sensitivity / Q000502:physiology*; D003936:Diagnosis, Computer-Assisted; D006801:Humans; D008027:Light; D008875:Middle Aged; D011601:Psychophysics / Q000379:methods; D011932:Reading; D015203:Reproducibility of Results; D014792:Visual Acuity / Q000502:physiology