364 The psychophysiological investigation of learning process on VDT

Abstract

This study investigated the effects of screen color combination, work-break schedule, and workpace on viewing distance during visual display terminal (VDT) work. Viewing distances of 40 subjects were estimated with a video recorder. Screen color combination significantly affected viewing distance, with red text on a green background resulting in the shortest viewing distance (47.4 cm). Viewing distance for the other four combinations — white-on-blue (60.3 cm), white-on-black (59.0 cm), yellow-on-blue (57.4 cm), and black-on-white (56.9 cm) did not differ significantly. The standard deviation of viewing distance was greatest for red-on-green than for the other color combinations. Work-break schedule also affected viewing distance. Subjects with a 5 min break for every 25 min of work had greater viewing distances than subjects with a 10 min break for every 50 min of work. Workpace had no significant effect on viewing distance. Red on green was inferior to all other color combinations. Implications of the results regarding VDT screen color design were discussed in terms of color difference and luminous contrast. In addition, a work schedule with frequent, short breaks may be employed to reduce VDT work problems. Relevance to industryThe VDT viewing distance is related to visual stress. Screen color combination, work-break schedule and workpace are factors that may affect VDT viewing distance. The application of results from this study may improve the performance and health of VDT worker.