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Circadian / Humancentric Lighting

In the last few years circadian and humancentric lighting have become the new buzz words. Why we are only talking about this now, and is this really important or is it all just hype?

“Humancentric lighting is defined by LightingEurope as a type of lighting that can benefit the biological, emotional, health, or wellbeing of people. This is achieved by dimming the smart light source, most likely an LED, to mimic the levels of sunlight throughout the day.”

Let us start with some background basics

Circadian rhythm is a naturally recurring twenty-four-hour cycle. When relating the circadian rhythm to lighting, we focus most on melatonin and cortisol levels.

Colour Rendering Index (CRI) is the ability of light source to reveal colours faithfully in comparison to an ideal light source. Even most LEDs with a high CRI will have a large blue peak and poorer colour reproduction in the reds. This is because 99% of the white LEDs on the market use a blue 440nm source, and then shift the colour spectrum with pigments and dyes.

Why only now?

About twenty years ago a photoreceptor called melanopsin was discovered that until now was overlooked. This receptor is not involved in our visual process, and only detects blue light (480nm) from the spectrum. In fact, even blind humans are affected by it. Under blue light exposure, this photoreceptor suppresses melatonin production. Melatonin hormones directly influences our alertness and ability to sleep.

LEDs have finally allowed us to take full control of the light spectrum. With this technology we can mimic different parts of the day. Incorporating warm and cool (2700°K and 6500°K) LEDs with the ability to control each of their levels individually we can adjust the light to any of the levels in the range.

The benefits achieved by being able to change the colour temperature are offset if we use a LED source with a low CRI. Recent innovations such as Sunlike take this to a new level by further reducing the blue peaks in the spectrum and enhancing the reds. By using a purple light source they can achieve a CRI of 96+.

How does it affects our lives?

Generally, we suffer from too little light at daytime and too much light at night. With the usage of humancentric lighting we have the ability to bring this back into balance by mimicking natural sunlight. Increasing productivity during the day, and assisting a natural fatigue at night is only the beginning. Studies have linked poor lighting to obesity, depression, sickness, stress, and even myopia.

At Oleant Lighting we are dedicated to providing fantastic designs with cutting edge technology. As of Q2 2020 we will have Sunlike tuneable white as an option in our luminaires.


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