Lighting is key to our life and impacts on wellbeing in several different ways.
This is becoming increasingly recognized in lighting design and the latest evolution in the field is Human Centric Lighting.
Human Centric Lighting has been one of the lighting innovations seen at Euroluce 2019 and is part of the WELL Building Standard (opened in a new window/tab) (the international reference for interiors and buildings that focus on health and wellbeing).
In short, it is just the beginning of a new way of designing and using artificial lighting.
But what does Human Centric Lighting exactly mean? And why is it important?
Human Centric Lighting has been effectively defined as
“lighting devoted to enhancing human performance, comfort, health and wellbeing”
Cit. Peter Boyce
To understand how and why it works, we need to make a little step back and look at how we as human beings relate to light.
THE IMPACT OF LIGHT
Light influences our overall wellbeing in 3 different ways.
Visually, it allows us to see, get a clear perception of the space around us and perform even meticulous tasks effectively.
Biologically, it influences our production of hormones, which in turn impacts on our sleep-wake cycle (the so called circadian rhythm).
And emotionally, it impacts our mood and overall comfort.
NATURAL vs ARTIFICIAL
Sunlight is not static. Instead, it varies during the day in both intensity and colour: from low and warm at dawn, to very bright and cool during the day, back to low and warm again in the evening.
And the way our body works is strictly linked to the variations in natural light. In particular, exposure to cool light (or blue light) inhibits our production of melatonine (the hormone of sleep) and stimulates the production of cortisol and dopamine (the hormons that make us feel awake). Which is why we naturally feel awake during the day and sleepy at night.
These days, we spend 90% of our lives indoors, and this makes it extremely important to care about the quality and the effects of our artificial lighting systems. Until now, artificial lighting has never really considered wellbeing and when compared to sunlight, standard artificial lighting tends to:
- provide too little light during the day (about ¼ of natural light levels!) and too much light at night.
- expose people to too much blue light at night time.
Overall this messes up with our hormone production, which is likely to cause sleep problems. And poor sleep can have a number of wellbeing and health consequences from bad mood and low memory, to lazier metabolism and immunosystem, up to cardiovascular diseases...just to name a few.
What Human Centric Lighting does is basically replicating sunlight variations in artificial lighting, creating a lighting system that:
- provides optimal eye comfort
- follows our biological cycle and
- makes the environment comfortable and pleasant to live in.
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The knowledge about the effects of sleep on health has been around for quite a while, so it might be fair to ask why this Human Centric Lighting concept is gaining traction only now.
Well, the reason is that today we have the technology and the knowledge to makes it both possible and efficient.
The introduction of LED light has made spectrum tuning (i.e. making light cooler or warmer) easily accessible and the efficiency of LED allows to add sophisticated functions to our lighting systems without having energy bills skyrocket as a consequence. Also, smart lighting technologies are making it extremely easy to control light. We can literally customize all the relevant aspects of light at the touch of a button!
On top of that, we also have a better understanding of how our sight works. In particular, we've discovered the existence of a third light receptor in our eyes that comes into play in the regulation of our circadian rhythm.
And now to the big question:
HOW DOES HUMAN CENTRIC LIGHTING WORK?
Human Centric lighting acts on the 5 aspects of light, adjusting them for our wellbeing. Let’s take a look at each one in turn:
Just like sunlight, Human Centric Light gradually increases when we wake up, shines bright during the day and gets – gradually – less bright as the evening comes.
This considers where the light comes from (overhead, wall flush etc.) and makes sure we get a comfortable environment without glare, dark areas or unwanted shadows.
Human Centric Lighting changes in colour (otherwise called spectrum content) during the day, delivering more blue light at daytime while getting warmer in the evening. For the records, this feature is often called tunable white.
Light colour changes according to the time of the day. Sensors can detect the level of light outdoors and adjust indoor light accordingly, allowing considerable energy savings as well.
How long we’re exposed to light makes a difference. In particular, light exposure at night can affect sleep quality and light intensity should decrease as the night approaches.
The result are super sophisticated light fixtures that automatically change light colour and intensity during the day and adjust according to outdoor light levels. All for our wellbeing! Pretty impressive isn’t it?
SOME EXAMPLES OF HUMAN CENTRIC LIGHTING
Let's finish off with a few examples of fixtures that reflect the Human Centric Lighting concept!
Artemide App (compatible with all Artemide fixtures with integrated LED)
Twiggy by Foscarini
Accordéon by Slamp
Curl by Luceplan
Poly Esagono by Olev light
Cover image by Thomas Allsop(via Unsplash) (opened in a new window/tab)