Human Centric Lighting: More Than A Design Trend – The Future

Paul Boken, BFA, LC, Vice President, Mulvey & Banani Lighting Inc.

A gene controls our daily biological rhythm.

Modern humans evolved from hunter gatherers near the equator, so we naturally function on a 12 hour light /12 hour dark schedule (12 hours of sunlight, sustained physical activity and regular meals, alternating with 12 hours of dark, sedentary time, and no food).  It is now understood more than ever, that a stable routine with consistent habits for food, exercise, and sleep is the foundation of a healthy, happy life.  Scientists have identified this foundation as our “Circadian Rhythm”, and now understand it down to the very molecular level that drives it. The Nobel Prize in Physiology or Medicine 2017 was awarded jointly to Jeffrey C. Hall, Michael Rosbash, and Michael W. Young for their discoveries of molecular mechanisms controlling the circadian rhythm. Using fruit flies as a model organism, the Nobel laureates isolated a gene that controls the normal daily biological rhythm.

Sleep, and the absence of light, heals our minds and our bodies.

The research is telling us that light is the strongest time cue “peacemaker” for the circadian rhythm. When I first read Dr. Satchin Panda’s “The Circadian Code”, I was elated to discover that my very lifetime passion, the medium of light, was at the core of this new understanding of our physiology. It goes something like this: the body is regulated by natural “pacemakers”.  Photobiologists discovered a light-sensitive protein in the eye’s retina called melanopsin, that detects light intensity or changing levels of light – this light pacemaker counts protons… it keeps score!  As the level of sunlight changes throughout the day, melanopsin signals our cerebral clock to shift into an active day pattern, or restful, regenerative night pattern.

It is accepted that daytime physiology/behavior and night-time physiology/behavior are incompatible processes and must be separated in time.   If we do not get enough light during the day, our pacemaker is more sensitive to low level light at night. Five lux (emanated from your phone screen, or TV) is enough to throw our rhythm off if we do not get good exposure throughout the day.

Another interesting book that got me fired up is Matthew Walker’s “Why We Sleep”– it explains in detail how sleep heals our mind and body, assists with storing and sorting our memory, amongst many other benefits.  We have lost our rhythm, sleep researchers warn, as a 24/7 lit society. Even when we are in dark rooms we stare at screens, and street lighting bleeds through most of our windows.  We are not in complete darkness in the evening, and to make matters worse we are in offices all day and are most likely not getting enough good quality white light in the day light. Watch my presentation at the IESNA Winnipeg AEFI Conference (Advanced Education Fly In) on Sleep to learn more.

How the lighting design industry can make a difference.

Stop designing and measuring light for the task!  Light levels falling on a desk on the horizontal plane are no longer relevant; light levels based on reading paper tasks are equally irrelevant. Today’s metrics should look at quantity and quality of light hitting our retina, and measure the effect on our biological comfort. The good news is that recent research provides metrics we can follow, there are new technologies that are helping us provide a higher quality, human centric light. In most cases, conventional LED will work to meet our needs if designed carefully, but new technologies with tuned spectrums may make it easier.

“My new personal mantra! Artificial light should: follow the sun; provide appropriate circadian stimulus; be comfortable; add visual interest.”

Green houses for plants use lighting with a calculated spectrum, designed to very specific requirements developed to optimize the space for plant health…based on biology. Yet typically, when it comes to designing interior space for humans we focus on efficiency, aesthetics and vision…not biology!  Not surprising, as there is a clear ROI/ business case for making plants grow faster and producing better yields. As of now, the ROI of human health and well being in the workplace is not as easy to measure…but the corporate world is beginning to grapple with this.

Some things we all can do…starting tomorrow! Give yourself bright full spectrum white light during the day, and dim warm light at night. Get outside, ensure you have good lighting at your workstation (if not get a good task light).  Use blue light filters on electronics. Get “f.lux” for your computer, turn on night shift or blue light filter on your phone. At night, turn the lights off!