Light controls just about all life on planet Earth. “All of us are entrained with day and night rhythms; the only exception is organisms in the deep sea and in caves where there is no light,” says Grace R. Denault, R.P.S.G.T., R.S.T., C.C.S.H., the director of education at Delaware Sleep Disorder Centers.
In pre-industrial times, we humans followed the sunrise and sunset, and many nonindustrial cultures today still follow these natural cycles. Denault explains that censors in our eyes have a pathway to a part of the brain called the suprachiasmatic nucleus, a bilateral structure located in the anterior part of the hypothalamus. “This controls our circadian rhythms, or the output of the hormone melatonin,” she says. “Melatonin goes up when it’s dark…and light turns off the melatonin supply.” In other words, we have a built-in rhythm, and sunlight is what resets it.
Of course, most modern routines don’t jibe with this cycle. Office jobs and getting kids off to school often require waking well before a winter sunrise, and then hitting the hay hours after its glow fades from the horizon. Popular science also tells us that seven to nine hours of sleep a night is essential to optimal health. (“Not getting enough sleep is linked to high blood pressure, risk of stroke, diabetes, COPD and other issues,” Denault notes.) So what can we do when we’re not following the light?
To support circadian rhythms, companies like Hatch have created sunrise alarm clocks (pictured above), which mimic a natural sunrise that slowly fills your bedroom with light—red, orange, yellow—about 30 minutes before it emits any sound. (Download the corresponding app on your smart device to select your preferred combination of light and sound to wake you, like Spring Sunrise with whistling birds, or Conquering Fuji with wind chimes.)
“This can be especially helpful when we’re waking up to the dark in northern latitudes,” Denault says. “It can help re-entrain and synchronize you when you’re not getting good natural light in the morning.” Putting this product to the test for several months, I’ve discovered I’m alert enough to hit the shut-off button before the sound ever comes on.
In addition to helping with shorter days, this is also good news for night workers, like nurses working the 7-to-7 shift. (Denault does advise waking when it’s still early enough to get ample bright light, if possible. This helps suppress melatonin to keep you going.) When relying on the Hatch to help you rise, just be sure to avoid settings with blue or green light, which adversely affect sleep.
