What is Circadian Lighting?

Human-centric, bio-dynamic, bio-adaptive, chronobiologic, biophilic, circadian, melanopic… whichever term you use, the premise of circadian lighting is to support our natural circadian rhythm by replicating natural light. Understand more about circadian rhythms here.

Light is the biggest synchronizer of our internal body clock; natural light is the best way to keep your body clock in sync. It is only relatively recently that humans have begun to live indoors. Humans lived in caves and used daylight to hunt and gather; therefore, day-to-day activity centred around daylight. However, in a world where we are now always ‘on’ and constantly digitised, it is easy for our rhythms to become out of sync, e.g. sitting under a bright white office light all day, in front of a bright computer screen, finishing the working day and sitting in front of the TV all night whilst checking your emails and scrolling through social media – it is understandable why as many as 16m UK adults are suffering from sleepless nights.

A study conducted by USA Today surveyed around 16,000 people across 14 countries in North America and Europe and found that around 90% of people spend close to 22 hours inside every day! This is a huge amount of time considering human beings are programmed to be in sync with natural light, e.g. sleeping at night and working during the day. It is, therefore, easy to understand how our natural body clock can become out of sync, given our lack of exposure to the outdoors. The impact of this is well documented; Web MD state that a circadian rhythm that is out of sync for a prolonged period of time has been linked to different disorders, including diabetes, obesity, and depression.

Hence, you begin to understand the need for indoor lighting that supports our circadian rhythms; lighting has evolved the same way that human lives have evolved - it adapts to our needs, the time of day, and by integrating sensors, it can also react to external cues.

The main aim of circadian lighting is that it provides, as close as possible, the same benefits as natural light. The timing, intensity, colour, and wavelength of light are key factors in regulating human circadian cycles and our sleep and wake patterns. To understand the benefits of circadian lighting in a live environment, watch our Heanor Park care home case study video.

Our ‘Circadian Plus’ solution is entitled ‘Plus’ because it delivers lighting that goes beyond just reproducing a (Western European) daylight simulation; it uses the control of spectrum to manage people's Circadian cycle.

Our algorithm mimics the colour and intensity of natural light over a 24 hour period; it automatically changes throughout the day, beginning with a warm amber light at sunrise, slowly changing into a cooler, brighter light during the day, before warming back into an amber light at sunset. In this way, specific colours of the visible light spectrum are managed precisely to provide circadian stimulus to building occupants in the morning and ensure that the lighting does not interfere with their natural body clock later, ensuring they get a better nights sleep.

(Knoerzer N/A)

The 24-hour lighting cycle follows a regular pattern, starting in the morning with the highest light levels significantly above normal indoor lighting between 7 am, and 10 am using a cool white light with a strong blue content.

The colour mix is then blended during the day to taper the blue content component towards the afternoon and then faded out for the late afternoon and evening, whilst maintaining as close as possible to a white light that appears much warmer. Brightness levels are also reduced in a carefully calibrated pattern from the early morning high.

After around 4 pm, the algorithm shifts towards an evening colour blend setting that is a warmer white colour. Later in the evening, it will move into the night-time setting at the warm end of the spectrum with reduced intensity levels.

Obviously, if circadian lighting is installed within an office environment, workers will only get the benefits for around 8 hours of the day, but this still has a profound impact on productivity levels and alertness. In fact, recent studies have shown that the productivity of office workers has increased by up to 20% following the introduction of human-centric lighting (otherwise known as circadian lighting).

However, a circadian lighting install in a care home environment allows residents to experience an immersive solution; therefore, the benefits are heightened.

There are many ways to measure circadian lighting effectiveness; you can read more in our article ‘How to Measure the Effectiveness of Circadian Lighting?’.

To understand more about how circadian lighting can benefit you within your industry, sign up for our newsletter, and you can download detailed research reports. Alternatively, get in touch here.

References:

Aviva 2017. As many as 16 million UK adults* are suffering from sleepless nights as a third (31%) say they have insomnia. https://www.aviva.com/newsroom/news-releases/2017/10/Sleepless-cities-revealed-as-one-in-three-adults-suffer-from-insomnia/. Accessed 07/07/20.

Walden, S 2019. The “Indoor Generation” and the health risks of spending more time inside. https://eu.usatoday.com/story/sponsor-story/velux/2018/05/15/indoor-generation-and-health-risks-spending-more-time-inside/610289002/#:~:text=While%20most%20survey%20respondents%20reported,22%20hours%20inside%20every%20day. Accessed 07/07/20.

WebMD N/A. Get in Touch With Your Circadian Rhythm. https://www.webmd.com/sleep-disorders/find-circadian-rhythm#:~:text=Circadian%20rhythms%20affect%20your%20sleep,diabetes%2C%20obesity%2C%20and%20depression. Accessed 07/07/20.

Knoerzer, L N/A. What is Circadian Lighting? https://www.thelightingpractice.com/what-is-circadian-lighting/. Accessed 07/07/20.

Lux Review 2019. Office with circadian lighting boosts productivity. https://www.luxreview.com/2019/05/22/office-with-circadian-lighting-boosts-productivity/. Accessed 07/07/20.