“Research demonstrates that light has a profound impact on people —
on their physical, physiological, and psychological health, and on their
overall performance — particularly in the workplace. And yet, despite
having an intuitive understanding of the importance of light, as well as
research-based data that proves its significance, we often fail to give it
adequate consideration when planning for the workplace”

facts and studies from Steelcase about light

http://www.oneworkplace.com/pdfs/whitepapers/TheImportanceOfQualityLighting.pdf