A Perfect Circadian Day

Publication Date: 

Keynote Speakers:
James R. Benya and Deborah Burnett 

The California Lighting Technology Center's second annual Don Aumann Memorial Lecture in Lighting Efficiency was held February 22 at UC Davis. This year's guest speakers, lighting and design experts James R. Benya and Deborach Burnett, presented the latest research in circadian science and implications for the growing field of sustainable design.

"The preservation of the night- and of the day- is very important to the maintenance of our health and well-being," says Burnett, explaining that our increasing lack of daylight during daytime hours and the growing prevalence of blue-rich light at night (from flowing screens and other sources) disrupts metabolic function, immune response, cognitive performance- even genetic expression. 

Benya and Burnett outlined "the monetary and human costs of circadian desynchronization," from lowered productivity and increased workplace accidents caused by fatigue to the link between depressed melatonin levels and increased cancer risk. They also explored the benefits of daylighting and "circadian adaptive lighting"- lighting that emulates or complements nature's cycles of light and dark, as well as the changes in color quality and direction that the sun's light waves exhibit over the course of a day. 

"This is a very exciting time to be a lighting designer," said Burnett, explaining that the growing body of research in photobiology poses both a challenge and an opportunity for those in the lighting field: to "go beyond aesthetics, and actually enhance human health and function."

The possibilities range from the simple to the technologically advanced, from lowering wayfinding lights (so as to avoid exciting certain cells in the eyes that cue wakefulness) to creating dynamic fenestration technlogies that integrate daylighting with electrical lighting, automatically adjusting brightness and color balance in harmony with circadian fluctuations. The applications vary too, from helping patients reduce hospital stay times or optimizing students' learning to minimize the photobiological impact of outdoor lighting to help restore ecosystems.