Effect Of Four Different Light Sources On Normal Color Vision.

Background: This clinical study explores the effect that three different lighting sources
have on color discrimination in people with normal color vision and no known ocular
disease. The purpose of the study is to assess how color discrimination may be affected in different lighting situations, possibly leading to occupational mistakes. Methods: Forty-nine subjects were tested using the Farnsworth Dichotomous test (D-15) under 4 different light sources; illuminant C (as a control), a sodium vapor lamp, an incandescent lamp and a metal halide lamp. The caps in the D-15 were arranged in a pre-determined random order for each light source. This order was held constant for each subject. The numerical order of the caps arranged by the subject was recorded and that sequence was used to calculate a color confusion index score using the color vision recorder and to record the number and type of errors. Results: There was a statistically significant difference between the mean CCl score of the sodium vapor lights and the incandescent lights as well as the sodium vapor lights and the metallic halide lights. However, no statistical difference was found between the means calculated for illuminant C and the other three light sources. Conclusions: One can conclude from this study that the differing light sources minimally affect the performance on the D-15. However, the light sources may have more of an effect if other types of testing are utilized.