- Lighting Solutions
Light exposure induces many effects on our physiology, such as helping to reset our biological clocks and improving mood.
Here are some ways by which light affects our alertness, safety and productivity, both at home and in the workplace:
Light tells the brain to be alert. As humans are diurnal (day-active) animals, light is associated with being awake and active. Light exposure is therefore a stimulant in humans, directly alerting the brain, reducing sleepiness and improving performance. This alerting response is very helpful if the light exposure is at the right time, for example while at work, but can be problematic if at the wrong time, for example, just before going to sleep.
Intensity and colour spectrum
In addition to timing, the intensity and colour spectrum of the light is also important. In general, increasing the intensity of indoor light will increase its alerting effects. Additionally, increasing the shorter wavelength (blue) content of indoor light will also encourage increased alertness. This is because the non-visual effects of light are linked to photoreceptors in the human eye that are sensitive to the shorter wavelength blue light. This is why changing the light intensity and spectrum can change the impact of indoor lighting on human physiology and alertness.
In the daytime, many of us will get too little light exposure but in the evening until bedtime, we tend to get too much. Ideally, we should expose our eyes to the same light-dark pattern each day with bright days (ideally from sunlight) and dark nights (minimising electric light after dusk and during sleep). However, given that we spend about 90% of our time indoor, we therefore need to consider the type of lighting we expose ourselves to throughout the day and night to ensure that we optimise exposure to the right light at the right time.
A number of examples of successful lighting interventions, or the disruptive effects of light, have been published in peer-reviewed medical journals. A selection is provided below.
Many lighting companies have also published their own reports or white papers showing similar benefits which are available at their websites. Please contact the CRC for Alertness, Safety and Productivity if you need additional resources.
Viola AU, James LM, Schlangen LJ, Dijk DJ. Blue-enriched white light in the workplace improves self-reported alertness, performance and sleep quality. Scand J Work Environ Health. 2008; 34(4):297-306.
Mills PR, Tomkins SC, Schlangen LJ. The effect of high correlated colour temperature office lighting on employee wellbeing and work performance. J Circadian Rhythms. 2007; 5:2.