• Testability of a Color Vision Screening Test in a Population with Mental Retardation

  By: Cotter, S. A., O.D., Lee, D. Y., O.D., Ph.D., French, A. L.

Purpose

The purpose of this study was to determine if the new validated color vision test "Color Vision Testing Made Easy" would be an effective means to screen for color vision deficiencies in a population of individuals with mental retardation.

Methods

"Color Vision Testing Made Easy" was administered as part of the vision screening sponsored by the American Optometric Association Sports Vision Section and Special Olympics International. The test was presented to Special Olympic Athletes, who are individuals with mental retardation or significant developmental delay, at four international sites: the world Winter Games in Toronto, Canada; the Regional European Swim Competition in Seville, Spain; and the Summer Games in Houston, Texas and Boston, Massachusetts, USA.

Nine test plates were presented sequentially, and at least 3 seconds were allowed per plate for the athlete to "find the circle". To pass the screening, the athlete had to correctly locate the circle on eight of the nine plates on the first trial. If fewer than eight correct responses were given, a second trial was conducted. To pass on the second attempt, the athlete was required to localize the circle on all nine test plates.

Results

The overall rate of testability was 93.2% for the 1078 athletes screened. The frequency of individuals identified as color deficient (7.5% of the males and 0.6% of the females) was similar to that expected in the general population.

Discussion

Until recently, commercially available color vision tests were not highly effective for screening young children, and therefore also presented problems for the mentally handicapped. The problem reported when using standard tests like the D-15, AO HRR, Ishihara Test, Dvorine Plates, and Anomaloscope to test mentally handicapped patients was a high level of false-positives (to many patients incorrectly identified as color deficient).

The primary difficulty for each of these color vision tests with mentally handicapped patients was trouble understanding the task required (e.g., understanding how to arrange the colored caps in the D-15 test).

The athletes tested using "Color Vision Testing Made Easy" during the world games in Canada represented many countries in which the primary language was not English. More than 95% of the athletes, however, were able to sufficiently understand the task required to complete the test. The testability was the same at the Regional European Swim Competition in Spain (95.7%), and even higher in the USA at the Houston, Texas games (98.7%).

Conclusion

The color vision test "Color Vision Testing Made Easy" was successfully completed by a very high percentage of Special Olympic Athletes. The results showed that the test was useful in screening this population for color vision deficiencies, and that the prevalence of color vision deficiencies was similar to the prevalence found in the general population.