Lighting, for humans

New lighting technology can take a tip from nature to get us back in rhythm

Today, a healthy lifestyle tends to involve choosing natural foods, using non-toxic products and materials or incorporating exercise into our routine. Rarely does light get a mention. But, naturally-inspired lighting could be the next frontier in wellness and design.


For thousands of years, human lives were driven by the movement of the sun throughout the day and year.  As light levels begin to fall, the body triggers the production of melatonin, a hormone that helps us fall asleep. While we sleep our bodies restore themselves. Then, when the sun comes up, sensors in our eyes trigger an increase in cortisol which acts as a neurophysical stimulant to wake us up. As the day wears on and the light begins to shift from cool to warm, Cortisol begins to leave our system and Melatonin production starts again. Circadian rhythm is the natural cycle our body goes through every 24 hours. All was good.

About 130 years ago, man invented artificial light. Since then, we have been wreaking havoc on our body clocks.  And the results have been alarming. Light, as it turns out, plays a major role in this Circadian cycle, and our modern lifestyles and technologies are disrupting these rhythms, resulting in startling health issues.


  • 54 million Americans, roughly 18% of the population, suffer from sleep disorders
  • Sleep disorders result in $63,000,000,000 in lost productivity each year
  • Sleep disorders have also been linked to obesity, diabetes, ADHD, heart disease, hypertension, PTSD and mental illness

While LED lighting has been a great step forward for sustainability and energy efficiency, there’s another lighting revolution yet to take place: Human-centric lighting. Human centric lighting is lighting that supports our Circadian rhythms.


The lighting industry is catching on. Tunable human-centric LED lighting is starting to break into the market. These systems and fixtures adjust color temperature throughout the day to match the changes in natural daylight. Although very new to the market, early results are intriguing.

  • In nursing homes with human centric lighting, there was a 5% reduction in cognitive deterioration, a 19% reduction in depressive symptoms, a 53% reduction in progressive functional limitation, and a 27 minute increase in sleep time
  • In a school in Germany, human centric lighting resulted in a 35% increase in reading speed and 45% reduction of errors on concentration tests
  • Although not a result of human-centric lighting, a recent hospital study showed that patients exposed to 46% more natural light used 22% less analgesic medications

More study is required, obviously, but human-centric lighting looks promising as a key element in environments designed to optimize our health, happiness, and productivity.

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