Effects of light on attention of fulltime daytime workers – a laboratory study

In addition to its impact on our circadian rhythm, researchers have investigated also alerting effects of light. While effects of light on sleep-wake rhythm and hormone cycles are well proven, evidence for effects on attention is less clear. Circadian effects of light can be best predicted by the activation of ipRGCs within the retina. Hence, we wanted to test the hypothesis whether an increase in activation leads to an improvement of attention during the day. Here we present a laboratory study that focused on alerting effects of light on fulltime daytime workers. We included a workday-like exposure duration and lighting scenes that comply with regulations for office workplaces. It was found that besides attention, participants' mood and perceived well-being were also affected. Contrary to our hypothesis, the results for different correlates of attention were best under lighting with the least activation of ipRGCs.