There is growing evidence that lighting can have a big non-visual impact on humans, affecting our mood and well-being. Adelle King explains how human-centric lighting is taking off.

Coloured lighting has been gaining increasing attention over the past few years, in particular the use of blue lighting to reduce crime, prevent suicides and increase the overall safety of public spaces.

Japan, England and Scotland have all installed blue LED floodlights at various railway stations and platforms as a cost-effective and simple way to prevent suicides and reduce anti -social behaviour.

Tokyo’s Yamanote railway line had blue LED lights installed at all 29 stations in 2009 and a paper published four years later in the Journal of Affective Disorder found there was an 84% decrease in suicides at the stations with blue lights installed.

This prompted Gatwick Airport in London to install its own custom-made 120W blue LED floodlights, which were manufactured by Minimise Energy, on train platforms in 2014. The floodlights bathe the platforms in blue light but have been positioned so that they don’t dazzle train drivers.

Scottish Network Rail then announced in 2016 that it would be trialling the installation of blue light sources at Scottish level crossings to help reduce an unexplained spike in suicides.

While the trial in Scotland is still ongoing and limited to two level crossings, early indicators from the Gatwick Airport trial have been good. Network Rail, the owner and infrastructure manager of most of the rail network in England, said in 2015 that the company had no reports of suicide-related incidents at the stations since the blue lights were installed. This is a big improvement on the year before, which was the worst year for suicides on the train lines in the southeast of England.

While there still isn’t a lot of scientific evidence to back up claims that blue light can prevent suicides, there are studies that have found blue lighting can make people calmer and less impulsive. For instance, research published by the University of Leeds in 2015 found participants’ pulse rates and blood pressure increased under red light but decreased under blue light, indicating that people felt more at ease under blue lighting.

These studies have given rise to the idea of human-centric lighting, which is devoted to enhancing human performance, comfort, health and wellbeing by focusing on how light can be used to suit a human’s circadian rhythm.

The colour and temperature of lighting plays a role in this but is just one facet that is considered when designing human-centric lighting solutions.

Philips Lighting is an advocate for human-centric lighting and has developed lighting solutions that benefit human psychology and physiology.

“Light can affect our well-being in ways that are visual, through photoreceptors in the eye’s retina, and non-visual, through our central biological clock,” says Philips Lighting country leader for Australia and New Zealand David Gardner.

“There are three scientifically proven benefits of light on life. Lighting helps us see better (visual), feel better (emotional) and function better (biological). Collectively, these give rise to psychological comfort.”

David says delivering the combination of the right light, with the right spectral content and at the right time means addressing five attributes – light intensity, colour temperature, light distribution, personal control and lighting design.

Although colour temperature is only part of this holistic view, it can have a big affect on people’s well-being.

“Being able to change or calibrate the colour of lighting will help boost one’s concentration, maintain optimal eye comfort, improve alertness and concentration, reduce sleepiness, increase activity performance and enhance cooperative behaviour in warmer light conditions,” says David.

Philips Lighting has developed two fit-for-purpose solutions around the principles of human-centric lighting, Philips Hue and Philips LED SceneSwitch.

Philips Hue is a personal wireless lighting system, which combines energy-efficient LED light with intuitive technology that enables users to control their lights from their smart devices. Philips Hue can also be voice-controlled and works with Apple HomeKit, Google Nest, Amazon Echo, Amazon Alexa and other virtual assistants.

“The Hue family primarily consists of the white and colour ambience range that covers the entire spectrum of 16 million colours,” says David.

Philips LED SceneSwitch features three light settings in one bulb, offering the ability to switch from functional bright lighting to natural lighting and then to a warm glow. A multiple-setting feature allows for task-lighting and ambient lighting in the household, while a built-in memory chip will memorise users’ last light setting if the switch is turned off for longer than six seconds. Since it works with existing switches, there is no need for re-cabling for a separate dimmer.

Human-centric lighting solutions are starting to be installed everywhere from homes and streets to large office buildings and hospital wards. While the International Commission on Illumination (CIE), the international authority on lighting, illumination and colour, says knowledge in this field is still premature, the organisation acknowledges that observations from laboratory studies have found it has beneficial effects on human health and performance.

“Human-centric lighting brings together an in-depth understanding of user needs, lighting applications and scientific insights to create evidence-based lighting solutions for optimal vision, sense of wellbeing and performance,” says David.