Christine starts her day in her cozy studio apartment. Her mornings begin with a special alarm clock that gradually simulates a sunrise, gently waking her up. By the time she switches on her bright white apartment lights, she already feels refreshed and ready to embrace the day. In her bathroom, Christine uses a mirror with bright white lighting and special high-colour rendering. This does not only help her apply her makeup with precision but also gives her a much-needed energy boost.
Our internal body clockwork - known as the circadian system - controls our sleep-wake cycles and many other processes throughout the day. Light plays a critical role in regulating this system, particularly in the morning. Bright white light helps synchronise our circadian rhythms, preparing us for an active day ahead.
Although Christine leaves her apartment feeling energised, her mood takes a slight dip during her subway commute. Poor lighting in the station dampens her spirits.
Lighting doesn’t just influence mood; it also enhances safety. For example, well-lit subway platforms help passengers spot potential hazards, like the gap between the train and the platform.
Christine arrives at her office, which features an open-plan layout flooded with natural lighting and bright white electric lighting. The setup keeps the team energised and productive. To further improve focus, each employee is provided with an adjustable desk lamp, allowing them to tailor the lighting to their individual needs.
Bright white light in the morning not only boosts energy but also reduces stress by helping our internal clocks stay in sync. However, it’s important to switch to dimmer, warmer lighting at least two hours before bedtime to wind down. This helps ensure the recommended eight hours of sleep, which enhances memory, creativity, problem-solving skills, and even social interactions.
Later in the morning, Christine delivers a presentation on how lighting impacts mood, productivity, and well-being. She ensures the meeting room’s lighting is optimized by setting the system to “presentation mode”. The lights in front of the screen are dimmed for better visibility, while the rest of the room remains brightly lit to keep attendees alert and engaged.
The 2017 Nobel Prize in Physiology or Medicine was awarded to Jeffrey C. Hall, Michael Rosbash, and Michael W. Young for their groundbreaking research on circadian rhythms. Their work revealed how light synchronizes our 24-hour body clocks, a phenomenon observed across nearly all living species. Environmental cues, known as zeitgebers (German for “time-givers”), reset these rhythms daily, ensuring alignment with the light-dark cycle.
During her lunch break, Christine and her colleagues take a short walk outside. Even a 15-minute stroll provides a refreshing boost and helps counter the post-lunch energy slump.
Outdoor light exposure - even on a cloudy day - can reach up to 10,000 lux, compared to just 500 lux in a typical office. This natural light not only improves mood but also helps regulate your body clock.
After work,
Christine meets a friend for dinner at her favourite restaurant. Talking about her
morning presentation on
lighting,
Christine notes how the restaurant’s dimmed lights and the warm light above the table
help create a relaxed atmosphere
for
enjoying their food.
Back home, Christine maintains this relaxed atmosphere by only turning on a floor lamp
and dimming the bathroom light as
she
gets ready for bed.
Because there isn’t always daylight when we need it, sometimes we must mimic it using electric lighting. With the right amount, timing, direction, and spectral quality, electric light can have a similar effect on our circadian rhythm as natural daylight.