The widespread adoption of electric light has disrupted the natural daily rhythm in light exposure. We are exposed to levels of light at night far beyond the range of star- or moon-light, while indoor lighting during the day provides a poor approximation of the intensity and spectrum of natural daylight. There is abundant evidence that these un-natural patterns of light exposure can alter daily variations in human physiology and behaviour, with knock-on impacts on health and wellbeing. We will introduce the biological processes linking light exposure to daily rhythms in behaviour and physiology, and consider how knowledge of this system can be applied to mitigate unwanted effects of light and to define the characteristics of healthy lighting.
Professor Brown is the joint lead author with Professor Kenneth Wright Jr at the University of Colorado on recent recommendations for daily light exposures. The recommendations are the consensus view from a workshop of international experts on 'non-visual' responses to light, which included Professor Lucas and UKHSA's own scientists. The paper is published in PLOS Biology and open-access: here
Professor Robert Lucas is the GSK Professor of Neuroscience in the Faculty of Biology Medicine and Health at the University of Manchester. He runs a laboratory undertaking fundamental and applied research in vision and circadian biology, and has a long-standing interest in the biological effects of light. He has served on committees at both CEN and CIE defining new metrics for light that describe its ability to elicit non-visual responses.
Timothy Brown is Professor of Neuroscience at the University of Manchester, in the School of Medical Sciences. His research focuses on the sensory control of the circadian system and other 'non-visual' responses to light, ranging from basic discovery science in animal models to translational application in humans. He has contributed to the development of new metrics for non-visual responses to light and led a recent expert scientific consensus defining associated recommendations for healthy lighting.