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Can the Farnsworth D15 Color Vision Test Be Defeated through Practice?

Ng, Jason, S., OD, PhD, FAAO*; Liem, Sophia, C., OD

Optometry and Vision Science: May 2018 - Volume 95 - Issue 5 - p 452–456
doi: 10.1097/OPX.0000000000001218
Original Investigations

SIGNIFICANCE This study suggests that it is possible for some patients with severe red–green color vision deficiency to do perfectly on the Farnsworth D15 test after practicing it.

PURPOSE The Farnsworth D15 is a commonly used test to qualify people for certain occupations. For patients with color vision deficiency, there may be high motivation to try to pass the test through practice to gain entry into a particular occupation. There is no evidence in the literature on whether it is possible for patients to learn to pass the D15 test through practice.

METHODS Ten subjects with inherited red–green color vision deficiency and 15 color-normal subjects enrolled in the study. All subjects had anomaloscope testing, color vision book tests, and a Farnsworth D15 at an initial visit. For the D15, the number of major crossovers was determined for each subject. Failing the D15 was determined as greater than 1 major crossover. Subjects with color vision deficiency practiced the D15 as long as desired to achieve a perfect score and then returned for a second visit for D15 testing. A paired t test was used to analyze the number of major crossovers at visit 1 versus visit 2.

RESULTS Color-normal subjects did not have any major crossovers. Subjects with color vision deficiency had significantly (P < .001) fewer major crossovers on the D15 test at visit 2 (mean/SD = 2.5/3.0), including five subjects with dichromacy that achieved perfect D15 performance, compared to visit 1 (mean/SD = 8.7/1.3).

CONCLUSIONS Practice of the Farnsworth D15 test can lead to perfect performance for some patients with color vision deficiency, and this should be considered in certain cases where occupational entry is dependent on D15 testing.

Southern California College of Optometry, Marshall B. Ketchum University, Fullerton, California *jng@ketchum.edu

Submitted: December 11, 2017

Accepted: March 14, 2018

Funding/Support: None of the authors have reported funding/support.

Conflict of Interest Disclosure: None of the authors have reported a financial conflict of interest.

Author Contributions: Conceptualization: JSN; Data Curation: JSN, SCL; Formal Analysis: JSN; Investigation: JSN; Methodology: JSN; Project Administration: JSN, SCL; Resources: JSN; Supervision: JSN; Writing – Original Draft: JSN, SCL; Writing – Review & Editing: JSN, SCL.

© 2018 American Academy of Optometry