Abstract
The present objective was to clarify the brightness condition of a computer screen to improve color accessibility of teaching materials by using ICT and reduces the sense of fatigue. Sixteen University students performed tasks employing a VDT in negative display mode using 8 grayscale conditions differing in brightness between the characters and background, and work efficiency, physiological, and psychological parameters were measured. Concerning work efficiency, no significant difference was noted in the amount of work completed or input error rate among the combinations. Blood pressure and heart rate showed no significant difference between the before and after task conditions with any conditions. The percent variation of the CFF value differed significantly among the 8 conditions, being low in combinations in compliance with international standards. The fatigue score increased in conditions with small differences in brightness and maximum brightness. These results suggest that conditions with an intermediate difference (difference in the L value according to the HLS color model: 160-224) rather than those with low and maximum brightness differences are appropriate for the grayscale negative display mode.
