Abstract
The purpose of this study was to identify which factors in lighting conditions affect discrimination of color in a clinical context. The subjects were 25 females (mean age 24.2 years old, SD 3.2) with visual acuity of 0.8 or higher. The experimental conditions comprised two light sources, a D65 color fluorescent lamp and an incandescent lamp, used at light levels of 1,000, 500, 200, 100, 50, 30, and 10 lx. Colored Landolt's rings placed against colored backgrounds were used to test color discrimination at these different light levels. As seen in the presentation color tables, the colors used were “RED-white”,“RED-orange”, and “RED-blue”, plus the standard “BLACK-white”. RED is the color of blood, and the background colors are the colors of clinically used linens. The results showed a significant increase in the rate of incorrect answers when an incandescent lamp was used to illuminate the “RED-orange” presentation color table at 100, 50, 30, and 10 lx, compared with the recommended 1000 lx level of illumination (p<0.05, p<0.001, p<0.001, p<0.001). The experimental results suggest that when observing patients, the use of a portable auxiliary light providing illumination of 200-1,000 lx or a light source with a higher color temperature would lead to fewer errors in color discrimination.
