The Future House – can advanced lighting improve our wellbeing?

In recent years, the lighting industry has undergone what some have called a revolution with the introduction of affordable, low-energy LEDs. Today, lighting can sense your movements, double as an artwork or a heater, or be practically invisible by day and illuminate at night. And while we are spoilt for choice in terms of options, the next revolution in lighting our homes and buildings is about improving our wellbeing.

Like natural sunlight, artificial lighting can strain our eyes, interrupt our circadian rhythms, increase our body temperature or, even, change our mood. Studies show that as we spend more of our time indoors – some of us are spending 90 per cent of our lives in artificially lit environments, which it is taking its toll on our health. So our lighting needs to have a more positive effect on our wellbeing.

While human beings have evolved in many ways, our bodies’ internal circadian rhythms – based around our relationship with the sun and moon light – is a hard-wired pattern within us all. They influence our mental abilities, sleep, energy levels and our metabolism, and when that natural pattern is disrupted, it can affect our general well-being and health. However, there a way of using lighting to enhance your natural body clock?

Human Centric Lighting (HCL) is a relatively new development with scientists currently trialling how lighting can affects our moods, either by calming or stimulating us at different times of the day or in extreme or stressful situations, as well as its ability to improve concentration and literacy.

In recent years, there has been controversy about whether too much blue light can interrupt our circadian rhythms. While blue light plays an important part in ensuring our body clocks work in time with the day and night cycle, being exposed to too much blue light in the evening can disrupt the body clock, causing poor sleep because it signals to your brain to suppress the production of melatonin, which is needed to help you sleep. It can also disrupt other dependent body processes, such as digestion and the menstrual cycle, although research is still ongoing. 

Some modern lighting, such as CFLs (compact fluorescent lamps) and LEDs (light emitting diodes) can produce relatively high levels of blue light, and computer and phone screens can also produce blue light. Blue light from lighting can be minimised by choosing LED or CFL bulbs with a ‘warm-white’ colour, rather than ‘cool-white’ or ‘blue-white’. Some bulbs are labelled with a ‘colour temperature’ and it is best choose a temperature of 2700 or 3000K. Some smartphones and tablets are fitted with a colour filter, which reduces the quantity of blue light emitted.

Different colour temperatures can create different moods in a space. Compare bright work lights that keep employees alert with a candle-lit dining table designed to induce romance and you gain a sense of how lighting can help change our feelings. 

Using LEDs with cooler colour temperatures in the evening can stimulate your brain to stay awake. Colour temperatures over 4000 Kelvin (K) are called cool colours and emit more blue light, whereas warmer colour temperatures of 2700–3000K signal to your brain to produce melatonin that helps you sleep – these have a more yellow/orange glow.

Shuji Nakamura won a Nobel Prize for inventing the blue LED, and he has suggested that Laser Lighting could be the future of lighting technology. It is currently being used successfully in car development – in headlights that are able to project light as far as 600m, which is much longer than the 300m managed by LED. However, laser light technology is still in its infancy and it’s not cheap, which has set it back from mass production. But that may change in the coming decades with more scientific research as the potential benefits of lasers are that they are more compact than LED diodes, they produce up to 1000x more light and consume one-third less electricity.

Within the lighting industry, research and debate is still ongoing about the spectrum of light and the complexity of integrated systems; however, the potential of human-centric lighting that responds to our circadian rhythms through automatic shifts in colour and brightness throughout the day seems like an obvious progression with which consumers will naturally respond. Start your morning with a warm, dim glow, leading to a cool, bright light during active working hours and, then, in the evening, your lighting shifts back to a warm glow, inducing relaxation. 

If the lighting in your home, office, car and gym was all in sync with your circadian rhythm; then, your environment would always be the right light for you and it wouldn’t even matter where you were in the world. It would use a combination of GPS and an indoor positioning system matched with a Fitbit or smartwatch; then, a phase response curve would help to gently shift your circadian rhythm by the correct amount as required.

And, while this type of system will likely become the norm, it is still unlikely to counteract circadian disruption completely as there are many other factors that can affect the cycle, such as stress or too much caffeine. However, it could help normalise the body’s cycle of sleep and wake, or help the body to adjust to a different time difference in the days leading up to travel. It could even help shift workers and those with disrupted sleep patterns to reduce any associated grogginess.

The potential of circadian lighting to positively impact people’s lives has some companies already recognising the benefits of alternating light spheres. The cabin lighting in the Boeing 787 ‘Dreamliner’ alternates between a warm white and a soft lavender colour to counter the effects of jet lag, while the dynamic lighting used in department stores can make food products look tastier or enhance the productivity of offices by changing the light according to the time of day. So the future could look brighter – or dimmer; let your circadian rhythm decide.