Human Centric Lighting & User Well-Being | Lighting Design

When it comes to LED lighting, we often think about the energy-saving benefits that LED technology has to offer. However, very few of us think about the impact it has on us humans from a well-being perspective.

Nowadays many of us work indoors, and as a result, we are exposed to a great deal of artificial light with low access to natural daylight which in turn can have a detrimental impact on our health. Eye strain, exhaustion, and weakening mental health are all issues that are linked to low access to natural light. This modern office-based lifestyle calls for a focus on lighting design.

Introducing Circadian lighting

A lighting system should be designed to tap into the proven cycles our bodies follow each day, based on the position, angle, and colour of natural sunlight at any given time. These cycles are known as circadian rhythms to lighting designers.

Circadian rhythm is known as a 24-hour internal clock running in the background of your brain and cycles between sleepiness and alertness at regular intervals.

Most people would have their most significant energy dip between 2 – 5 am when they are fast asleep and after lunchtime between the hours of 1 – 3 pm. However, these rhythms can vary from person to person depending on the type of person – e.g. are you naturally a night owl or a morning person?

The natural circadian rhythm allows us to produce the following:

Dopamine for pleasure, alertness & muscle coordination.
Serotonin to regulate impulse control and carbohydrate cravings.
Cortisol for stress response.
Melatonin for consistent sleeping patterns.

When it starts to get dark at night, your eyes send a signal to a part of your brain called the hypothalamus, signalling that it is time to feel tired. Your brain subsequently sends a message to your body to release a natural hormone called melatonin, which makes your body tired.

Your circadian rhythm works best when you have regular sleep habits, like going to bed at night and waking up in the morning at a similar time from day to day – this also highlights the necessity for human-centric lighting in the workplace.

A circadian lighting design starts with activation upon awakening, then subsequently creates a state of alert in the early hours of the day that stimulates concentration in daily activities. As the day progresses, it should encourage relaxation, finally leading to sleep.

From this, we can deduce that by using different colour temperatures, as well as various light spectra, throughout the day, we can produce a tangible impact on the subjects physical states and behaviours that favours natural cycles, even in artificially lit spaces.

What is human-centric lighting?

Human-centric lighting can improve a person’s well-being, productivity and motivation-levels. Light stimulates us, influences our mood and impacts our activity levels accordingly to the colour spectrum, intensity and timing of the light. If a person spends a lot of time indoors (Like most of us nowadays), the effects can be significant as mentioned above. Light is the most crucial element to control our circadian rhythm, so it is essential to acknowledge this when designing a lighting system.

Exposure to light in the morning is the most effective – It tells our biological clock that the day has begun and that bodily functions need to be activated. In contrast, light exposure in the evening will cause melatonin production to be suppressed and make it harder to fall asleep. For example, cool white light with high intensity at the beginning of the workday assists in shifting our sleep phase forward and helps to reset our biological clock. Tuneable white light is essential to countries with limited daylight throughout winter, including Ireland. Human-centric lighting systems have also been linked with reducing seasonal affective disorders as well as boosting short-term concentration and alertness when applied correctly.

When we are in an office setting, the light is often set to a constant correlated colour temperature, which is inconsistent with or circadian rhythm. Without exposure to dynamic lighting, the circadian rhythm is often disrupted.

In our opinion, a balance must be met in terms of individual and automatic control to ensure the maximum circadian effect and minimum risk of misuse. To allow for more individuality, we often recommend tuneable white free-standing lamps or suspended luminaires by or above each workstation for best results.