The effect of dynamic light on human alertness

The main goal of the present study was to compare the impact of dynamic and static light on work performance and means of different measures of alertness. Ten participants experienced four sessions. Each session had a different lighting: 6000K static light, 9000K static light, CCT- low-frequency dynamic light (cycle = 4 hours, CCT between 6000 and 12000 K) and CCT- high-frequency dynamic light (cycle = 2 hours, CCT between 6000 and 12000 K). Each session lasted 5.5 hours. Altogether, 12 testing methods were used and they can be divided into four categories: questionnaire, task performance, physiological methods and biochemical methods. The present results suggest that dynamic light generated a higher alertness than static light, and CCT-high-frequency dynamic light had a stronger impact than that of low frequency CCT-dynamic light.