Rhythm of Light

Rhythm of Light

It has been a while since we discovered our third eye. In fact, it was 2002 when a German University scientist discovered a new set of sensors in the retina that triggers mood responses in our mind and body when exposed to light. The findings initiated a revival in the interest of circadian rhythms in the lighting world and with it a prediction that smart lighting would dictate lamp design into the next decade. However, some fourteen years later, one is left wondering ‘what happened’ with little evidence that the science has been embraced by lighting sector.

It would seem that light means more to us than just brightness – it has a far more profound effect than merely aiding vision. The SCN cell is hardwired directly into our internal body clock within the brain which research has discovered is incredibly accurate and sends vital signals throughout our anatomy. Each individual’s clock will run a 24 hr cycle but it is often not exact – it can vary in terms of accuracy. Our bodies recalibrate this clock with light every day. It is why blind people have the added challenge of becoming out of sync with day and night. Until 150yrs ago we were all happily dependent on natural daylight, firelight, and candles. Since then we have been changing our natural pattern with artificial illumination. But we ignore the importance of this light cycle at our peril.

circadian-2-thumbnail-olThis SCN cell is most stimulated by the wavelength of light within the blue spectrum. Give it a blue-enriched diet then it’s firing on all cylinders. Give it red and we’re getting ready to sleep. Naturally – if we are over-stimulated at night we cannot rest and understimulated in the morning we can be ineffective. Take the whole body clock into account and a lack of balance can lead to stress, depression and other illnesses.

As an example of a good balance of light, NASA operated strict circadian lighting control within the International Space Centre; prior to a spacewalk, the astronauts will subject themselves to a period of 6500K blue-enriched light, invigorating the body. To induce sleep they will bathe in very warm (blue free) light.
Despite all the science, the truth is that the methodology of blue and red light has not taken hold of ‘lighting industry’ imaginations – judging by a recent statement by the International Commission for Illumination things are still slow to ignite.

“…despite great promise, there are as of yet no protocols for providing specific “circadian” benefits in buildings for general populations.”

In a practical sense, there is an absence of affordable or accessible systems on the market – apart from some mid-market Building Management Systems. Yet I believe we can work with circadian know-how in all our projects at a relatively low cost. Using a range of differing colour temperature LED lighting units including; strips, downlights, and spots. Operating on several separate lighting circuits, with a compatible dimmer, an interior lighting scheme can be easily tuned to suit the time of day.


Why not talk to us about your affordable lighting options for your next project. Remember, clever lighting schemes don’t always need to be smart!

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