Shining a Light on Wellness

Change the body, change the mind.

How does wellness relate to light? Hopefully, we can all recall high school textbook descriptions of the visual system consisting of the cones and rods living in the retina at the back of the eyes. Stimulated by light, this system is responsible for our photopic (day) and scotopic (night) vision.

In 2002, Samer Hattar, a chronobiologist and leader in the field of non-image-forming photoreception, and his colleagues made a significant contribution to our understanding of vision when they defined the role of melanopsin in the retinal ganglion cells (also known as ipRGCs or Intrinsically photosensitive retinal ganglion cells). These cells are found in the lower part of the retina, which corresponds to the upper portion of our visual field. Interestingly, the ipRGCs have a linear response to light, unlike the visual system (cones and rods), that continuously adapts to the environment. ipRGCs are most sensitive to short wavelengths, and are responsible for the constriction of pupils and the release of melatonin in response to light. Melatonin is essential as it’s the hormone responsible for regulating our sleep-wake cycle. The suppression of melatonin (by activation of the ipRGCs) encourages dopamine, serotonin, and cortisol production.

The link between vision and wellness

The duality of our visual system is similar to breathing in that it has a bidirectional effect on our nervous system. When we experience stress, our breathing becomes shallow. This starves our system of oxygen, triggering adrenaline that prepares our body for action. On the flipside, a known method for de-stressing is deliberately slowing our breathing, which slows the heart rate and calms the nervous system.

A similar mechanism applies to the visual system. When stressed or anxious, we often experience tunnel vision; a decreasing of our visual aperture, causing us to focus on specific thoughts or emotions. Alternatively, when we are relaxed, our vision becomes panoramic and we experience a wider field of view. Think of the calming effect of watching a sunset or viewing a beautiful vista.

We are multidimensional creatures that rely on many complex systems working in unison. Our body and mind constantly make subtle and dramatic changes responding to the environment at conscious and subconscious levels. The more we understand these systems and their dependencies, the more we can use them for our benefit.

The link between vision and wellness

The duality of our visual system is similar to breathing in that it has a bidirectional effect on our nervous system. When we experience stress, our breathing becomes shallow. This starves our system of oxygen, triggering adrenaline that prepares our body for action. On the flipside, a known method for de-stressing is deliberately slowing our breathing, which slows the heart rate and calms the nervous system.

A similar mechanism applies to the visual system. When stressed or anxious, we often experience tunnel vision; a decreasing of our visual aperture, causing us to focus on specific thoughts or emotions. Alternatively, when we are relaxed, our vision becomes panoramic and we experience a wider field of view. Think of the calming effect of watching a sunset or viewing a beautiful vista.

We are multidimensional creatures that rely on many complex systems working in unison. Our body and mind constantly make subtle and dramatic changes responding to the environment at conscious and subconscious levels. The more we understand these systems and their dependencies, the more we can use them for our benefit.

Lighting Technology and Visual Wellness

It’s only been 20 years since the start of our understanding of how light affects our sleep-wake cycle. Over the same amount of time, technology has dramatically impacted our lives. With the dot-com boom in the early 2000s, we’ve seen countless technological advances, from solid-state storage, battery technology, wireless communications (including Bluetooth), the internet, social media, and smartphones. And for the lighting industry, it is, of course, LED lighting.

We don’t always get things right.

The early adopters of LED lighting found themselves with expensive products providing moderate performance, but now we see high-quality LED everywhere. As a result, there is a vast ecosystem of mature products that would have never been possible with traditional lamp technologies. The downside, however, is the complexity and decision fatigue associated with this abundance.

Ironically, the marketing department is always the first to cut through the noise. I’m sure most lighting professionals can recall the early presentations on circadian lighting—this new technology aimed at boosting employee productivity enough to cover the cost of the new lighting system. I remember a pitch for tuning LEDs to 6000K at certain times of the day to provide an energy boost to the workers.

Science-led lighting technology

Fortunately, the literature has caught up to marketing; or perhaps the demand for science-based evidence has increased. In 2017, the lighting technology and solution partners Tridonic, iGuzzini, Fagerhult and Zumtobel teamed up with Aalborg University, Copenhagen, to develop and scientifically validate the concept of Double Dynamic Lighting (DDL). This concept utilises different colour temperatures for direct and indirect components to simulate the dynamic qualities of daylight. The study provided several design recommendations to implement DDL, including dynamic controls to emulate sky variations, combinations of direct and diffuse lighting components, colour temperatures and light levels. In addition, this study shows the benefit of strategically applying the technology based on a deep understanding of the biological effects.

There are also new types of LEDs that are specifically tuned for the non-visual effects of lighting. These LEDs still achieve the benchmarks for visual lighting (e.g. high colour rendering) but are either blue-enriched or blue-depleted depending on the application. They are usually accompanied by additional metrics to measure the effectiveness of the activation of the ipRGCs. Clearly the trend is pointing towards a human-centric approach to lighting. But how do we make it all work?

Lighting Control

In my 15+ years in the entertainment industry, two things were certain: if you want something to work, you run a cable to it, and if it’s not working, it’s usually the cable. However, the dominant market leaders in lighting controls are quickly challenged by new and emergent technologies, especially those that leverage open-source collaboration and wireless connectivity.

There is a demand for lighting control systems to be the backbone for other building services such as sensor networks, indoor location systems, and wireless data. Furthermore, our customers now want to analyse the data from these control systems to understand space utilisation, perform preventative maintenance, and capture all sorts of efficiencies. This challenge was seen as an opportunity for two ex-Nokia engineers who co-founded an open-source, wireless controls system known as Casambi.

Lighting control parameters have evolved beyond on, off and dim. We now need to consider all sorts of dynamic parameters such as time of day, prevailing conditions, colour mix, specific user preferences, and more. We can’t always predict how a space will be utilised, so our control systems need to be as responsive, adaptive and individualised as the people that use the spaces we design.

Existing frameworks and standards

Having frameworks and standards establishes consistency and collective purposes to improve lighting that supports wellness. For the lighting industry, it is the question of how do we standardise something that’s so individualised?

Industry bodies and rating systems cover many layers of standards, such as Green Star, WELL, and LEED. I was fortunate enough to work on Australia’s first WELLv2 rated residential building. However, we found some challenges while working through the rating system as it was primarily geared towards commercial buildings.

One of the main features of our solution was the use of low glare, dusk dimming luminaires. Dusk dimming follows a predetermined curve from warm white (3000K) to ultra-warm white (1800K), which emulates the behaviour of a traditional incandescent globe and only requires a single dimming channel. We felt this was the best outcome in a residential setting. It would prevent undesirable combinations and simplify controls and commissioning in a volume construction environment – as Tony Robbins says, “complexity is the enemy of execution.”

The cost to wellness

Now that we have the complete ecosystem of science, technology, and controls, one issue remains – the cost. Currently, there is a high barrier to entry to implementing human-centric lighting schemes.

Value management. Option engineering – call it what you will, but it’s usually the time when the finance team gets the red pen out, ready to make some cost savings. We may be able to make compromises and substitutions to reduce cost, but these will reappear as complexity costs or costs to the project’s outcome. Despite the research, science, and cost-benefit, sometimes, human-centric lighting is just out of reach.

Zero and low-cost approach

What can we do today to improve our lives and benefit from the abundance of knowledge and technology?

At this point, maybe we can tone down the analytical mindset and focus on the mood we’re creating with our lighting systems. As lighting designers, we know how to evoke moods through light. We can create bright and energising spaces, dark and moody, and everything in between.

Many people would be surprised to know how little light is needed at night, especially overnight. I have young children and an old dog, so I’m constantly moving around at night. I find it essential to maintain low light levels to help me get back to sleep. However, this is a challenge in and of itself because most consumer lighting products are too bright, the wrong colour, complicated, expensive, or poorly made.

The best solutions I have found so far include; a short length of smart LED strip set to a dim red/orange colour, battery-powered motion sensor nightlights that have been modified to reduce the brightness (and they’re still a little bit too bright), and battery-powered fairy lights strategically draped over furniture. I encourage you to experiment and explore what works best for you. The main things to look for are very low brightness, low mounting height and warm/red/orange colour temperature.

Personal adjustment to light – Light viewing

Dr Andrew Huberman, a neurobiologist whose work focuses on the visual system and light-mediated activation of the circadian system, encourages us to view natural light outdoors for 10-30 minutes every morning. He says it’s the most important thing any of us can do for our mental health, promote metabolic well-being, and promote our hormone system’s positive function.

Light viewing in the late afternoon also supports sleep. Though this seems counterintuitive, it’s said to lower the retina’s sensitivity in the late evening hours when we may be viewing devices, displays or other light sources.

We can make a conscious effort to avoid lighting environments, such as viewing or interacting with devices when we should be preparing our system for sleep. You may think that a quick check of the phone overnight doesn’t hurt, but it has been shown that it can take as little as 20lx to disrupt your sleep cycle, and the effect on your retina can persist long after viewing light. Light viewing overnight (typically 10 pm-4 am) is highly disruptive to sleep and has been shown to negatively affect learning, memory, and the immune system.

I believe these creature comforts can be relatively straightforward and cost-effective. Viewing natural light is a zero-cost option that we can implement straight away. We can also take a conscious approach to our light viewing behaviour. We can audit our day and think about how our mood and energy levels might be linked to our environments. If we can’t change our setting, there may be other ways to implement a personalised approach to lighting.