To determine the frequency and type of color vision defects in a large group of randomly selected older people using two versions of the D-15 and to examine the agreement between the two tests.
The Adams desaturated D-15 test was administered under Illuminant C (MacBeth lamp, ∼100 lux) to a group of 865 individuals aged 58 to 102 years (mean, 75.2 ± 9.1 years). No exclusion criteria, other than the reported presence of a congenital color defect, were applied. Testing was binocular with habitual near correction. If any error was made on this test, the Farnsworth D-15 was administered under identical conditions. On both tests, a color confusion score of 30 or higher was considered failing, and for those failing the test, color defect type (blue-yellow, red-green, or nonselective) was determined using the method of Vingrys and King-Smith (1988).
The majority (60.8%) of the people tested passed both tests. For the sample as a whole, the failure rates of the Adams desaturated D-15 and the Farnsworth D-15 were 36.2% and 20.76%, respectively. As expected, for both tests, failure rate increased markedly with age. Among those who failed both tests, 17.5% of the population, the proportion of specific agreement for red-green and blue-yellow defects was high, 88%. The vast majority of those failing either or both tests had blue-yellow defects, in agreement with previous studies.
Blue-yellow defects were quite common among the aged, becoming increasingly prevalent with increasing age. More people failed the Adams desaturated D-15 than the Farnsworth D-15, but among those who failed, the proportion of blue-yellow defects was similar for the two tests, approximately 75%. The agreement between the two tests in identifying acquired red-green and blue-yellow errors was high.