Lighting in indoor environments: Visual and non-visual effects of light sources with different spectral power distributions

Since the end of the 1990s, good quality lighting was that which balanced the needs of humans, economic and environmental issues, and architectural design. Recent studies aimed to find a correlation between environmental lighting and human performance and health, with positive results. What is known, is that insufficient or inappropriate light exposure can disrupt standard human rhythms which may result in adverse consequences for performance, safety, health. By studying the relationship between human physiology and light, research in photobiology has advanced to the point where some attempts to foresee what the lighting practice will be in future. The question is if lighting practice and lighting practitioners are ready for changes. This paper has the aim of introducing the recent discoveries in photobiology to those interested in lighting design, starting from a critical overview of traditional parameters since now used in lighting applications and then presenting a new theoretical approach to introduce non-visual parameters for lighting applications.