• Project number: F 2448
• Institution: Federal Institute for Occupational Safety and Health (BAuA)
• Status: Completed Project

Description:

Studies have shown that light not only influences people’s circadian rhythm, but also changes their alertness. These non-visual effects of light are thought to be mediated mainly by a specific type of photoreceptor in the retina, the intrinsically photosensitive retinal ganglion cells (ipRGCs). The ipRGCs contain the photopigment melanopsin, which is highly sensitive to light in the short-wavelength region of the spectrum.

This project investigated whether light can be used to support employees’ alertness at work. In a laboratory study with 42 subjects, three light scenarios were examined that differed in their potential for activating ipRGCs. Contrary to expectations, the light with the least activation resulted in better performance on the attentional tasks. In addition, the mood and the self-assessed comfort of the subjects also improved.

The influence of light on alertness should therefore be seen in a broader context rather than solely focusing on the activation of ipRGCs. Future studies should explicitly investigate effects on the emotional system to generate more holistic knowledge and enable the design of supportive lighting that equally addresses alertness and well-being in the workplace.