Lighting, Colour Temperature and it’s effects on the body

Light, the body and the sleep/wake cycle
Over recent years, industry professionals have become increasingly aware of the vast impact that light has on our physiological, psychological and emotional wellbeing. To stay healthy, alert and productive, people need to have regular circadian rhythms and keep to a constant sleep/wake cycle as directed by our exposure to certain light wavelengths during the day.

The two key hormones affected by light are the sleep hormone melatonin, and the stress hormone cortisol. When waking up in the morning, it’s important to get our bodies to release enough cortisol to promote alertness. Into the evening and towards sleep, people need to halt the production of cortisol and encourage the release of melatonin to help them get to sleep.

To do this, the body needs access to bright light with blue wavelengths in the first few hours of waking up. Brightness and intensity may be decreased throughout the day and by night, blue light must be eliminated and amber tones increased and by the time we head towards sleep we should eliminate light altogether.

Humans have evolved to use the sun’s light to dictate their sleep/wake cycle, so correct lighting design for daily living and health is about mimicking sunlight. This means that careful attention must be paid to colour temperature and spectral distribution, light intensity and spatial distribution. The light source is important as the spectral distribution changes with the type of lamp.

LEDs and their role in healthy lighting design
LED light sources are the best at providing the spectrum of light that the body requires, and they’re the most versatile. LED light sources with tuneable colour temperatures are one of the newest evolutions to market-  this means that the colour temperature can be altered throughout the day via the one light source, rather than using multiple light sources. Our supplier RAAT won the 2014 Red Dot lighting award with their Tuneable LED track light, Abaco and our supplier Halla won the 2015 Red Dot lighting award for their tuneable LED linear profile, Sant.


Information has been gathered from various resources including our suppliers Philips, Osram, RAAT and HALLA.