Circadian lighting and the importance of a good night’s sleep 

The profound effect of the right type and quantity of light on the human sleep/wake cycle 

Since Signify started partnering with the Mercedes-AMG PETRONAS Formula 1 Team in 2024 to drive our shared passion for sustainable technology and responsible innovation, we’ve learned a great deal about the punishing Formula 1 racing season schedule and the unique challenges that drivers face to achieve and maintain peak performance. The team drivers and trainers, in turn, have learned a great deal about how light can help them do just that. 

Every year for 10 months, starting in March to December, the Mercedes-AMG PETRONAS Formula 1 Team participates in 24 races on five different continents. With all the shifting time zones, night and day races, and long airline flights, jet lag becomes a serious issue—and if it isn’t addressed effectively, racers quickly find themselves at a competitive disadvantage.  

Addressing jet lag requires that drivers manage their sleep and waking cycles effectively, no matter where in the world they find themselves.  

What is jet lag, anyway?

Of course, Formula 1 drivers aren’t the only ones affected by jet lag. You’ve likely experienced jet lag, too, and its unpleasant effects are likely familiar to you: fatigue, inability to concentrate, unpredictable spikes in hunger, irritability, and—perhaps worst of all—disturbances to your sleep/wake cycle.

Jet lag can be a serious nuisance, but do you know what causes it? It’s not the second cup of coffee you had at the airport, and it’s not that drink you had with your in-flight meal. It’s actually caused by disruptions to your circadian rhythm.

The circadian rhythm is a 24-hour internal “body clock” that governs the sleep/wake cycle and other vital aspects of human physical and mental health. When you shift multiple time zones quickly, the circadian rhythm gets out of sync, and you experience the symptoms of jet lag. 

Fortunately, jet lag goes away after a few days, and you start to feel better. This means that your internal clock has readjusted to the current time zone, and your circadian rhythm is more or less aligned with the 24-hour day in whatever part of the world you happen to be.

What’s light got to do with it? 

You may not know it, but light plays a profound role in regulating the human body clock. The right type and intensity of light at the right time of day helps to keep the circadian rhythm properly aligned (or entrained). The wrong type and intensity of light, on the other hand, can wreak havoc.

Light produces obvious and profound visual effects in us. It also produces non-obvious but equally profound non-visual effects. There are receptors in the eyes, alongside the well-known rods and cones, with a direct line to the region of the brain—the suprachiasmatic nucleus of the hypothalamus—that regulates the human circadian rhythm.

This third kind of receptor contains a photopigment known as melanopsin. Melanopsin has a lot to do with the functioning of “sleep hormones” like melatonin and tryptophan, as well as with cognitive and affective processes in general. Melanopsin is most sensitive to short wavelengths of visible light—that is to say, blue light. Not surprisingly, the amount and timing of the blue light we get during each 24-hour period has a lot to do with our circadian health.

Curiously, the eyes’ melanopsin receptors don’t work in tandem with the human visual system, but entirely independently. We know this because experiments have demonstrated the melanopic effects of light even on people who are completely blind.

So, what kind of light do you need, and when? The science—supported by randomized controlled trials and research-based recommendations—indicates that proper circadian entrainment requires a good strong dose of bright blue light for a couple of hours in the morning, when we need to be awake and alert, and dimmer, warmer (non-blue) light in the evening, when we’re getting ready for sleep.

The experience of jet lag without getting on a jet 

Unfortunately, you don’t have to have actual jet lag to experience the symptoms of jet lag. Many of us, including office workers and shift workers, spend 90% of our time indoors, and so may frequently experience impaired performance, brain fog, and sleep disruptions—not exactly because we aren’t spending enough time outdoors, but because we’re not getting the right kind and intensity of light at the right time. 

To address this situation, Signify has innovated a number of solutions using a combination of dynamic LED luminaires, flexible controls, and science-based lighting recipes designed to cater to the circadian needs of people who spend most of their time under artificial light. With our circadian lighting solutions, we can deliver the optimum kind and quality of light throughout the day for focus, productivity, and high performance. Our solutions can be used in application areas as diverse as office workspaces, hospitals, schools, hotel guest suites, and stadium locker rooms. 

Signify’s innovative circadian lighting solutions 

The following sections detail three of Signify’s circadian lighting solutions, how they work, and what they can do for you. 

NatureConnect
NatureConnect gives a skylight illusion that turns dark or windowless areas without access to natural daylight into engaging spaces by mimicking daylight. NatureConnect replicates a view to the sky, using light scenes that boost energy levels and that help windowless spaces feel in sync with nature. One study shows that NatureConnect has a positive impact on alertness and vitality of workers. Another study confirms that people who work under NatureConnect without access to daylight miss daylight less. 

While NatureConnect cannot be formally classified as daylight according to EN-17037, the European standard for daylighting in buildings, it meets the standard’s maintained illuminance requirements for indoor workplaces as well as its highest recommendation levels for daylight provision. 

A NatureConnect skylight is designed to be indistinguishable from a real window, creating a daylight effect and increasing feelings of spaciousness. The blue sky experience uses light recipes with high melanopic levels to maintain high performance while at the same time offering functional lighting, and improving light uniformity and distribution to minimize shadows. This helps support work on tasks that require precision, such as examinations and data analysis in healthcare settings.

Learn more about NatureConnect in office, healthcare, and hospitality environments around the world >

Interact circadian lighting

Interact connected lighting offers circadian lighting capabilities for its office, education, healthcare, hospitality, and sports systems. These capabilities are implemented using dynamic, Interact-ready connected LED luminaires—tunable white and full-color—and evidence-based lighting recipes (dynamic lighting scenes) designed to have a positive impact on mood, performance, and overall well-being.

Circadian lighting with Interact contributes to requirements laid out in healthy building standards such as BREEAM and WELL. Achieving healthy building certifications increases the value of commercial properties and makes them more inviting to high-value employees. In hospitality settings, Interact uses specially designed lighting behaviors to help guests get the best night’s sleep possible and wake up naturally and refreshed in the morning. In sports facilities, uniquely designed lighting recipes for dressing rooms can enhance focus, intensity, or relaxation as needed. In educational settings, circadian lighting can help improve performance on tests and reading speed. And in healthcare, circadian lighting can support the healing process, lower errors rates, and reduce patient elopement incidents.

Learn more about Interact circadian lighting >