2011 - Daylight Symposium
DAYLIGHT – VISUAL COMFORT AND NON-VISUAL FUNCTIONS by Mirjam Münch
Fellow of the VELUX Foundation at the Laboratory for Solar Energy and Building Physics
Within the last decade it became evident that light through the eyes is essential for not only visual but also non-visual photopic functions. One of the most important non-visual functions of light is the daily entrainment of the circadian clock by environmental light conditions. As most people spent the majority of their time inside buildings, room light quality defines many physiological and behavioral functions in addition to vision related properties. This is true for acute responses to light as well as for circadian (and probably even longer lasting) light effects. Another emerging question is to what extent visual and nonvisual functions might interact. We tested whether visual comfort is associated with subjective alertness, mood and physical wellbeing. By comparing these effects under two different office lighting conditions in healthy young subjects during daytime, we found that associations of visual comfort with alertness, mood and wellbeing were not only dependent on lighting conditions but also on time of day. We also found repercussions of different light conditions during the afternoon on cognitive performance in the evening. We conclude that for optimum environmental lighting conditions both visual and non-visual aspects of light need to be integrated into architectural and building science.
Mirjam Münch, received her Ph.D. in Neurobiology from the University of Basel in 2006, under the supervision of Prof. Dr. C. Cajochen and Prof. Dr. A. Wirz-Justice, (Centre for Chronobioloy, Psychiatric University Clinics, Basel). For her doctoral thesis she investigated circadian and homeostatic effects of age and monochromatic light on human sleep. After graduation, she left to the US for a position as a Post-doctoral Research Fellow at the Brigham & Women’s Hospital (Division of Sleep Medicine), at Harvard Medical School in Boston (Prof. Dr. J.F. Duffy). At the end of 2008 she moved back to Switzerland and began as a Fellow of the VELUX Foundation at the Laboratory for Solar Energy and Building Physics, (EPFL) in the research group ‘Daylighting and Perception’ led by Prof. Dr. J.-L. Scartezzini. Since joining this interdisciplinary group, several research projects were designed and a new scientific network in the framework of (day-) light and circadian physiology was built up. The aim of her current position at LESO-PB is to bridge the gap between neuroscience and circadian physiology on the one hand and potential applications in building science and architecture on the other hand.