Understanding Circadian Lighting: Enhancing Health and Well-being with Natural Light
Optimising Your Environment for Better Sleep, Energy, and Productivity

Circadian lighting, also known as human-centric lighting or tuneable lighting, refers to a lighting system designed to support the body's natural circadian rhythm, which regulates the sleep-wake cycle and other biological processes. It aims to mimic the dynamic changes in natural daylight throughout the day, providing appropriate light levels and colour temperatures at specific times to promote alertness, productivity, and better sleep.

Circadian lighting systems typically utilize LED technology and allow for the adjustment of light color temperature and intensity. They are capable of providing cooler, bluish-white light in the morning and daytime, which promotes wakefulness and alertness, and warmer, reddish-white light in the evening and nighttime, which supports relaxation and sleep readiness.

How Circadian Lighting can help you?

Improved Sleep Quality: Circadian lighting can help regulate your sleep-wake cycle by providing the appropriate light cues at different times of the day. Exposure to cooler, bluish-white light in the morning and daytime can enhance alertness and suppress melatonin production, helping you feel more awake and focused. Conversely, exposure to warmer, reddish-white light in the evening and nighttime promotes the production of melatonin, facilitating better sleep quality and a more restful night's sleep.

Increased Daytime Alertness and Productivity: By simulating the natural changes in daylight, circadian lighting can help boost your daytime alertness, focus, and productivity. The cooler, bluish-white light in the morning and daytime stimulates the brain, making you feel more awake, energized, and attentive. This can be particularly beneficial for tasks that require concentration, such as work or studying.

Regulation of Biological Rhythms: Our bodies rely on the regularity of light and dark cycles to maintain various physiological processes beyond sleep, such as hormone production, digestion, and metabolism. Circadian lighting helps regulate these biological rhythms, supporting overall health and well-being.
Mood Enhancement: Light has a significant impact on mood and emotional well-being. Circadian lighting that mimics natural daylight can help improve your mood, reduce feelings of fatigue, and enhance your overall sense of well-being. It can provide a more uplifting and positive environment, particularly during darker seasons or in spaces with limited access to natural daylight.

Personalization and Flexibility: Circadian lighting systems often offer the flexibility to customize and adjust lighting parameters to suit individual preferences and needs. You can program the lighting system to gradually transition between different color temperatures and intensities throughout the day, aligning with your personal routine and preferences.

To benefit from circadian lighting, it is important to integrate the system into your living or working environment. This can involve using smart lighting solutions, such as tunable white LED bulbs or fixtures, or implementing lighting control systems that automatically adjust lighting parameters based on the time of day

See below for a recent article about this in the Times newspapeΩ    z

‘Warmer’ bulbs help light way to the Land of Nod

LEDs and other sources of blue light can keep you awake at night, scientists say, so reduce their use in the evening to calm the brain

If you struggle to sleep, it might be worth changing the bulb in your bedroom.
Scientists believe the type of lightbulb in your home may be having a distinct impact on the duration and quality of your sleep.
The impact is so significant that when they changed the bulbs in care homes, they found they could reduce falls by more than 40 per cent, as residents were sleeping so much better.
Modern bulbs — particularly the most readily available “cool” LEDs — often contain high levels of blue light, which interferes with sleep patterns.
“The blue light photoreceptor in the eye is hardwired to the body clock,” said Professor Steven Lockley, a neuroscientist at Harvard Medical School in the United States and an adjunct professor at the University of Surrey’s Surrey Sleep Research Centre. “To alert the brain, you ramp up the blue content and intensity of light. But if you want to calm the brain and make yourself more sleepy, you dim and reduce the blue light and make it more red.”

The impact on our sleep of blue light from mobile devices, particularly before bed, is well established. The light suppresses the secretion of melatonin, a hormone that controls the onset of sleep. But Lockley, originally from Stone, Staffordshire, said many people may not realise how lighting in the home also affects sleep.
“Old-fashioned incandescent lights were very red-enriched, with very little blue light,” he said. “But as we’ve moved to fluorescent, then compact fluorescent, and now LEDs, there’s much more variety in the spectrum of light. Some people may buy a lightbulb without realising it has a lot of blue in it and have it on in their homes in the evening.”
LEDs offer a “flexible” solution, he said. Bulbs with a “warm” tone contain more red light, for example.

Lockley has demonstrated how significant the impact of light is by changing bulbs in care homes in the US. His team installed an automated lighting system that boosted blue-light levels in the day and reduced them in the evening. The study, conducted at four care homes and involving 758 residents, found the number of falls fell 43 per cent after the lighting change, according to results published in the Journal of the American Medical Directors Association. Lockley and his colleagues found that the main reduction happened at night. Because residents were getting more and better sleep, they were not only getting up less after dark but also were more alert in the daytime, and therefore less prone to toppling.
Lockley is planning a bigger trial in the UK.

The automated system cost $1,700 (£1,340) per resident but he said: “You can achieve this at home . . . by putting the blue-enriched light in the ceiling for the day and then have your bedside lamp blue-depleted in the evening.”