Effect of Enclosed Lighting Environment on Work Performance and Visual Perception

This study aimed to validate non-visual effect of light on work performance and give recommendation for enclosed environment. Based on literature review, nine light conditions with three high correlated color temperature (4000 K, 6500 K, 10000 K) × three illuminance (300 lx, 500 lx, 750 lx) were compared in this study to select the best lighting for work. Two tests were used to measure work performance, including cognition test of STROOP and attention test of PVT. KSS and subjective evaluation were used to assessed alertness and visual perception as well. 12 males at their twenties were recruited and completed experiment in the windowless lab. Results: The results showed better cognition of STROOP task under 6500 K and 10000 K vs. 4000 K and promoted sustained attention with shorter reaction time of PVT under 500 lx and 750 lx vs. 300 x. Subjective alertness showed no significant differences between any two of the lighting conditions. Visual perceptions reported the best visual comfort, satisfaction, and preference under 500 lx. Subjective evaluations for three CCT levels were not significantly different from each other. Conclusion: As a result, office lighting with CCT of 6500 K or 10000 K with illuminance at 500 lx was recommended to ensure both task performance and visual perception in the enclosed working space.