The Evolution of Light: From Incandescent Bulb to IoT Based Smart and Human Centric Lighting! – Part 2.
Apr 05, 2018
In our earlier article, we have already explained about smart lighting. Smart lighting has a huge scope, but when it comes specifically to indoor lighting - Human Centric Lighting (HCL) is more applicable. Now, what is HCL?
This is the latest concept in lighting. It's actually a type of lighting that can benefit the biological, emotional, health or wellbeing of people. This is achieved by dimming and changing the CCT (correlated colour temperature) of the smart light source by mimicking levels and CCTs of sunlight throughout the day.
Depending upon the sun's lighting levels and the changing of CCT throughout the day, different types of hormones during different time of the day is generated by our body. Such secretion of hormones define our body clock which is also called as "circadian rhythm". Our body clock is naturally aligned towards the sunlight. So, post the sunset a hormone called melatonin starts getting generated in our body. The generation of this hormone makes us feel sleepy. It reaches a substantial level at around 10 pm in the night and it attains its peak between 2 am to 4 am early in the morning. Thus, we have the deepest sleep from 2 am to 4 am in the morning! Likewise, when we get up early in the morning another hormone called dopamine starts getting secreted in our body. This hormone makes us feel good, happy, rejuvenated and charged. That's how we start our day with fresh energy.
A photo protein called Melanopsin exists in the retina of our eye. Melanopsin is linked with the Suprachiasmatic Nucleus (SCN) part off the brain, which in turn controls the pituitary gland. The pituitary gland controls our body clock. When the circadian rhythms are thrown out of gear, a hormone called Cortisol is secreted in our body. Cortisol is a stress hormone that disrupts the body system and causes high BP, pulse rate etc. The heart rate also goes up causing severe discomfort.
Our body clock is at its best under sunlight. Unfortunately, our life style is such that our body is exposed to long hours of artificial lights. If our body is subjected to more of artificial light, which is not in line with sun's behaviour throughout the day, our body clock starts malfunctioning. For example, if there's more of blue content in the spectrum of artificial light, (which is a possibility with LEDs), it will suppress the generation of melatonin hormone. If this continues for a week, then our sleep will get disturbed thus disrupting our body clock.
We have now realised the importance of human centric lighting on our productivity as well as our wellbeing. Hence, nowadays we are working on HCL which will regulate the hormones of our body, and meet our visual and non-visual needs even under artificial lights! Recently, Bajaj Electricals has launched a product, Dominto Dyna, which offers human centric lighting solutions for office environments. You can read more about the product here.