A professional audience attended the LUCTRA® round of experts organised by DURABLE at the German Olympic and Sport Museum in Cologne on 22 October. The panel of speakers on "Perfect Day Light" consisted of leading experts such as Dr. Michael Peters from the business consultancy Peters’ Projects and former Managing Director of Messe Frankfurt, the keynote speaker Dr. Dieter Kunz, Head Physician of Sleep and Chronomedicine at St. Hedwig’s Hospital in Berlin and Managing Director of Intellux GmbH, Prof. Dr. Ulrich Kuipers, Faculty of Electrical Engineering and Information Technology at South Westphalia University of Applied Sciences, Prof. Dr. Günter Horntrich, founder of yellow design and Professor of Ecology and Design at the International School of Design in Cologne until 2013, and the host, Horst-Werner Maier-Hunke, Managing Director of DURABLE. About 200 visitors attentively followed the presentation by Dr. Kunz about the great significance of light for personal well-being, and the information given by Prof. Dr. Horntrich and Prof. Dr. Kuipers about the sophisticated combination of design, technology and function. The lively discussion afterwards showed the great relevance of this topic for all of the guests. During the subsequent get-together, due attention was also paid to refreshments and to an inspirational exchange of opinions.