Increased illuminance at the workplace: Does it have advantages for daytime shifts?

Abstract

An increased illuminance at the workplace is often said to be linked to an increase in productivity. We investigated this relationship in 23 workers on a production line in a car factory. Measurements of visual performance (visual acuity, colour vision and contrast sensitivity), a physiological assessment of alertness and subjective assessments of four parameters of well-being were made during the daytime shift under three illuminances (500 lux, 1500 lux and 2500 lux). The physiological alertness results and all but one of the subjective parameters showed no significant differences between the three illuminance conditions. Subjective alertness was the only parameter that was rated to be significantly greater at 2500 lux than at 500 lux. The utilisation of higher illuminances in the workplace should be carefully considered before being implemented.