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A comparative study of the color vision testing plates issued by Keeler "the city university color vision test" and the D&H color rule

1 January 1978


A relatively new color vision testing book utilizing color confusion has been produced by Keeler Instruments Ltd. and designed by Robert J. Fletcher. The purpose of this thesis is to test the quantitative screening efficiency of the Keeler plates as compared to presently used clinical screening methods. The tests used for comparison are the AO HRR, Dvorine, D&H Slide Rule and the Nagel Anomaloscope. Examining the Keeler plates we find that comparatively they scored worse than both the HRR and the Dvorine in both determining and classifying defectives. Subjects which were defective all reported that the task was difficult but were often able to correctly identify the match. The Color Rule when examined with the authors' criteria did screen as effectively as the Dvorine and HRR. In fact the color rule more efficiently screened anomalous subjects than both the Dvorine and HRR.


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