This study investigated the effects of ambient illumination conditions (illumination color and illumination intensity) and background color on visual performance (character identification and reading comprehension) with TFT-LCD screens. Results of Experiment 1 indicated that all the three independent variables had significant effects on mean percentage of character identification. Mean character identification performance was best under white light, 500 lux, and blue background. In general, the backgrounds with primary colors had better mean character identification performance than the middle-point colors and gray. Results of Experiment 2 indicated that the illumination intensity and background color had significant effects on mean text comprehension performance for reading comprehension. Mean text comprehension performance were higher under 500 lux and blue background. The backgrounds with primary colors had better mean correct answers than the gray background. According to the results, white light, normal ambient illumination and a background with primal colors seemed to be the optimal conditions. If the yellow ambient light is necessary, using blue as the TFT-LCD background color of will provide better performance. The Pearson product-moment correlation coefficient indicated that short-term visual task measurement might be suitable to evaluate the visual performance. 
Effects of ambient illumination conditions and background color on visual performance with TFT-LCD screens