IN A previous report1 we discussed the general situation with respect to polychromatic test plates for the detection of defective color vision, pointing out the advantages and limitations of this type of test and the need for care in administration. Stress was laid on the following four important sources of error which, aside from defects in the tests themselves, account for part of the failure of the tests to screen out all persons with defective color vision : (1) disregard of the critical importance of illumination; (2) careless and inefficient administration; (3) incompetent and invalid interpretation of results; (4) misapplication of the tests to fields for which they were not intended, or the expectation of more from the tests than they are capable of, or designed for, yielding.
In that report a critical evaluation was made of the fifth edition of the Ishihara test for the analysis and detection of
LE GRAND H. HARDY, GERTRUDE RAND, M. CATHERINE RITTLER. TESTS FOR THE DETECTION AND ANALYSIS OF COLOR BLINDNESSIII. The Rabkin Test. Arch Ophthalmol. 1946;35(3):251–270. doi:10.1001/archopht.1946.00890200257005