Effects of illuminance and color temperature of a general lighting system on psychophysiology while performing paper and computer tasks

This study provides optimal correlated color temperature and illuminance to increase comfort and reduce fatigue by considering psychological and physiological quantities when working with paper and electronic devices. Task performance was not affected by devices and lighting conditions. The subjective evaluation revealed no significant differences between devices. The participants felt tired with an illuminance of 300lx and preferred a correlated color temperature of 5000K or 6500K and an illuminance of 750lx. However, the participants were more comfortable at 3000K and 750lx than at high correlated color temperature and low illuminance. The adjustment method demonstrated that comfortable illuminance does not show a significant difference in correlated color temperature and that paper requires significantly higher brightness levels than a screen. The adjustment method and subjective evaluation found consistent results for comfortable illuminance. Physiological measurements revealed that oxygenated hemoglobin was higher for computer than for paper use. In addition, illuminance of 500lx and correlated color temperature of 5000K resulted in the least fatigue. Although the subjective evaluation found no significant differences in fatigue, physiological measurements revealed that illuminance and correlated color temperature were accompanied by the least fatigue. Therefore, the results of this study highlight the necessity of creating a work environment that considers psychological and physiological quantities based on the work medium.