A few years ago I learned about the health benefits of Circadian Lighting from articles that appeared in CE Pro, a trade journal for custom electronics professionals.
It developed the theory that lighting which imitates the daily rhythms of the sun results in enhanced health benefits. These can include better sleep, improved immune system and mental health benefits. As I understood it, the theory was based on the fact that, as evolving mammals, our ancestors lived for thousands of years in the open air under the direct influence of these Circadian rhythms. Industrialization has reduced, sometimes eliminated entirely, direct daily contact with nature. Our bodies’ natural systems have not adapted to the changes in our environment. Our internal clocks are still attuned to draw strength from exposure to the daily changes in ambient light by aligning them with natural Circadian rhythms. These dynamic light conditions can now be reproduced electronically.
What made this so significant to me at the time was that tunable LED lighting had just come to market.
With tunable lighting, it is possible to control lights to change not only intensity but colour. That means that the orange tints related to sunrise and sunsets can be reproduced with artificial lights, and with modern automation systems those changes can be timed to correspond to waking up and going to sleep times.
Now in a recent article by Nick Boever for CE Pro, I find that there is more to it. He says that there is “a photosensitive cell in the back of our eye that processes both visual and non-visual stimuli for the brain” and that since its discovery in 2002, scientists have found that it regulates more than just the Circadian Rhythm. It directly affects our endocrine system, adrenal system and our metabolic functions. This has led to the development of a parallel to Circadian Light applications, which professionals refer to as Human Centric Lighting. He quotes lighting researcher Peter Boyce as saying that this development allows “lighting devoted to enhancing human performance, comfort, health and wellbeing, individually or in some combination.”
Boever goes on to list several impacts to human health can be addressed by Human-Centric Lighting.
It can be used to eliminate glare and flicker from lights, which have been shown to have a negative impact on health. The Seasonal Affective Disorder (SAD) that many of us are about to cope with through the coming winter, can also be helped by Human Centric Lighting solutions. The effects of stress and depression can be lessened and, apparently, its use in some schools increases cooperation and participation among school students.
Human Centric Lighting can directly affect mood and learning, which makes its study ideal for business and education applications.
But my area of interest is in private homes rather than institutions. To learn more about this, I followed a related link in the CD Pro article to one written by lighting designer David Warfel (lightcanhelpyou.com). He says we unconsciously experience stress and fatigue when coping with glare and shadows, even when theoretically there is enough light present for the task (e.g. reading, near work). He suggests that, rather than turning to tunable lighting, we can reduce such problems by placement, such as providing two overlapping task lights, slightly behind the work position, to cancel out each other’s shadow and reduce glare. It really takes an experienced lighting designer who fully understands light source placement and interaction to approach these challenges effectively, but in the absence of such a professional, he says “The key is to think about the light source in relation to our eyes. Keep it behind or below your eyes. Overlap the beams to counteract shadowing. That’s it, really.”