Novel Classification of the Degree of Color Vision Defects in General Practice: Simulations of Cap Number and Saturation of the Farnsworth Dichotomous Test D-15

Abstract

Objective: In most eye clinics, while severe to moderate color vision defects are diagnosed with the Farnsworth dichotomous test D-15 (D-15 test), moderate to mild color vision defects are detected with the Farnsworth lantern test. This study aims to propose a new classification of the degree of color vision defects in general practice by simulations of the cap number and saturation of the D-15 test. Methods: We performed the simulation of the modified D-15 tests with a reduced number of test caps (9 and 6 caps) to compress a hue circle based on the color confusion lines for the hypothetical participant. In addition, we performed another simulation of the modified D-15 test with modified chroma test caps (chroma 6 and 2). Results: The color confusion along the confusion lines was more likely to occur as the number of caps decreased in our simulation model. The modified chroma D-15 test did not affect the results of this study. Conclusion: The results of this study reveal that the D-15 test with a reduced number of test caps has possibilities to classify patients with moderate or mild color vision defects.