When the sun has already set before you’ve even started to think about what to have for dinner, it’s easy to feel a bit off. That’s because your body has its own internal clock—your circadian rhythm—and it’s modulated by sunlight. “Circadian rhythm has an effect on when we fall asleep, when we wake up, the quality of our sleep, and the quality of our alertness in the daytime,” explains Doug Steel, a neuroscientist and an adviser to lighting brand Brilli. In winter especially—but also anytime, really, especially if you work in an office—it’s hard to get the right amount of natural light to stick to a healthy sleep cycle.
Enter circadian lighting: A design practice that incorporates as much natural light as possible and supplements it with bright lights in the daytime and dimmer lights in the evening to correspond with the sun. It’s been embraced by designers, doctors, and architects alike—because it works. One 2015 study on hospital lighting concluded that natural light supplemented with LED lightbulbs resulted in a quicker recovery for patients and increased comfort for everyone. A 2017 study on dimmable LED lights in classrooms made for better learning environments.
There are plenty of ways to do it at home. Instead of relying on a single overhead stagnant light, consider one with a dimmer. Use brighter, cooler bulbs (around 4,000K, according to Lauren Spear, director of design at Alma) that are evocative of daylight in the morning and afternoon, and when the sun is setting, switch over to warmer, dimmer ones (like Brilli’s Wind Down bulbs or even red-toned bulbs, which have been shown to increase melatonin production)—or maybe you might just want to get a color-changing bulb that can do it all.
But swapping your regular bulbs for LED ones isn’t necessarily a cure-all, says Norman Rosenthal, M.D., the psychiatrist credited with first describing seasonal affective disorder (SAD) in the ’80s. Sure, circadian lighting could be enough to improve your sleep and energy, but it might not be enough for people who experience seasonally specific feelings of depression in the wintertime. In those cases, he recommends a SAD lamp whose surface area is at least one foot square (which will ensure you get enough light), a UV filter to make sure it’s gentle on your eyes, and a level of brightness that is “not too dazzling but not too low” that you can position 18 inches to two feet away from your body and turn on for about 20 minutes a day.
This, he says, is a great remedy for “the winter blahs,” especially if you start using it around October. “But it’s never too late,” he adds. “One huge benefit is if you start using a light now, you can get a jump-start on next winter.” Because even if it’s not spring yet, winter is coming.
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