The light is our best friend. Light is essential for life. We need light to get up in the morning. That is why it is easier for us in summer than in winter. Light gives us energy, we feel fit and look forward to the day with excitement. Light makes us happy. In a research programme, healthy people let themselves be illuminated by an artificial light source for one hour every day during one month. After the experiment you felt even better, fitter and more balanced than before. Natural light offers us a wide variety of facets. From the soft first rays to the hard, bright midday light to the warm sunset.