Whether it’s the soft glow of your computer monitor, an errant light seeping through the gap under the door, the aggressive streetlamp, or the brief flash that comes from your silenced smartphone—light, it seems, is Public Enemy No. 1 when it comes to sleep. In fact, the National Sleep Foundation reports that light exposure is “one of the most important factors” when it comes to regulating—and deregulating—our body’s natural sleep-wake cycle (aka circadian rhythm). Here’s how to use evening darkness (and bright daytime light) to improve your whole family’s sleep.

Hello Darkness, Sleep’s Best Friend

Nighttime is for sleep, and it’s not just because the clock tells us so. When the light begins to dim, a signal is sent to the pineal gland in our brain that bellows, “It’s time to release the sleep hormone melatonin.” In short, the lights go down, melatonin goes up, and so does our drowsiness. But our instinct to sleep when it’s calm and dark is not just about melatonin. Thousands of years ago, folks who fell asleep easily—even when it was loud, bustling, or bright—were the ones most apt to be attacked by a predator. On the other hand, folks who stayed appropriately alert to outside stimuli survived…and so did their genes! That’s why in order to spur melatonin and make our inner-caveperson feel comfortable enough for sound sleep, adequate darkness is key. Here’s how to achieve it:

  • Wear an eye mask. Did you know that simply shutting your eyes does not create enough sleep-inducing darkness? A report in the journal BMC Research Notes found that light can still easily filter through closed eyes, suppressing melatonin. That means, a sleep mask can be just the ticket to not only spur melatonin, but to condition your brain to recognize that everything’s safe and calm for sleep. Experts note that wearing an eye mask for sleep can help you fall asleep faster and increase the amount of ZZZs you get. Furthermore, new research in the journal Sleep found that regularly wearing an eye mask may also improve memory and alertness in the morning. While anyone can benefit from wearing a sleep mask, it’s thought to be especially helpful to those who are suffering with insomnia, folks who work the night shift, and pregnant people. (A 2023 study found that wearing a sleep mask improved sleep quality and sleep duration of pregnant individuals.)

  • Use blackout curtains. Light from the sun, the moon, streetlights, your neighbor’s porch—all of it—can seep right through regular curtains or blinds and disrupt your sleep. But blackout curtains are designed to keep the shine out. They’re made with thick, room-darkening fabric designed to “block the majority of external light,” according to the Sleep Foundation. In a pinch? You can use painter's tape to temporarily secure a black trash bag to the offending window.

  • Stow your electronics. Shut off all the lights in your bedroom and look around for any sources of light, such as a charging station, a digital clock, a humidifier—and of course your phone, tablet, computer, or television. Then decide: Can you cover the light, or do you need to move the item outside your bedroom? If you’re someone who (inadvisably!) falls asleep with the TV on—and relocating it is impossible—at the very least, see if your television has a sleep timer that automatically turns off after a period of time.

The flip side to all this good-for-sleep darkness is sleep-sapping nighttime light exposure that essentially pauses melatonin secretion. This resets your body clock to keep you awake when you should be winding down! Additionally, research shows that folks exposed to high levels of nighttime light are more likely to be dissatisfied with their sleep quantity and quality than those who snoozed in low/no light.

Embrace the Slow Fade to Black

Before you slide between the sheets in your dark room, it’s important to prepare your brain for sleep with a gradual introduction of darkness. Here’s how to do that:

  • Turn on night mode. Starting 2 to 3 hours prior to bedtime, flip your phone on “night mode” to start minimizing your exposure to blue light, which has a significantly larger impact on delayed melatonin release than other forms of light.

  • Get your dim on. Research shows that dimming the lights in your home 4 hours before bedtime can help keep your circadian rhythms on the path to sleep. If that’s too big of an ask, the National Sleep Foundation recommends dimming the lights—and turning off screens—at least one hour before your usual bedtime.

  • Try a red light. When you need light at night to read or do your evening stretches, consider going red. Dim, warm-color light can help with relaxation and getting into the right mindset for sleep. Plus, experts note that a low-intensity red light likely has no negative effect on melatonin levels. As such, “using red lights before bedtime may help you sleep better.”

Daytime Light and Nighttime Sleep

While avoiding light at night is important to successful sleep, it’s equally important to seek the light during the day. That’s because exposure to natural light during the day—and especially in the morning—properly calibrates your body clock, priming your brain for sleep at night. Numerous reports have found that daytime exposure to light increases evening sleepiness, helps folks nod off more quickly, improves sleep quality, and ups slow-wave sleep, which is synonymous with deep, restorative rest. Unfortunately, only 50% of adults report spending at least 30 minutes in bright light most days of the week, according to the National Sleep Foundation’s 2023 Sleep in America Poll. To help get more daytime light…

  • Take a 15- to 30-minute walk first in the morning.

  • Drink your morning coffee outdoors.

  • Walk the dog an extra 10 minutes.

  • Eat lunch outside.

  • Take a stroll after your lunch break.

  • Exercise outside.

  • Situate yourself next to a window during the day.

  • Keep your shades open when possible.

Children’s Sleep and Light Exposure

The way light and darkness affect melatonin secretion and sleep applies to both adults and children. The only difference is that, when compared to grownups, children are even more sensitive to light (thanks in part to their large pupils) and its negative effects. In fact, research has shown that evening exposure to light suppresses melatonin production twice as much in children than adults. And another study found that preschoolers’ melatonin levels were 88% lower after an hour of bright light—and they remained low at least 50 minutes after the lights were turned off for bedtime.

All this melatonin suppression means kids are getting less sleep than they should, which is a scary thought. Babies and children need regular and adequate sleep so their developing brains can process new skills and experiences, consolidate memories, improve motor development, vocabulary, attention, and mood…and so much more. To help shield your child from the sleep-sapping effects of evening light, follow the tips above, and…

  • Don’t forget the bathroom. Dimming the lights in the living room and bedroom is important, but since kiddos are brushing and bathing before bedtime, it’s important to keep the bathroom light dim, too!

  • Rethink your nightlight placement. There’s no need to toss the nightlight! “Many children feel safer if they can see familiar surroundings when they wake at 2am, not just a gulf of darkness,” says pediatrician and sleep expert Dr. Harvey Karp. But instead of placing your child’s nightlight right next to their bed, put it out of their direct line of sight, like partially blocked by furniture or low to the floor. This way, your little one benefits from the comforting glow, but they aren’t exposed to a close-up light that can.

  • Turn on the red light. Exposure to the standard white or blue light in most nightlights can disrupt your child’s sleep by inhibiting the release of melatonin. A better idea? Choose a dim nightlight that emits a warm, red-ish, or orange-ish glow. The award-winning SNOObie nightlight and sound machine allows you to choose between eight soothing colors, including sleep-helping red and orange.

  • Save screens for the morning. If you’ve fallen into the habit of offering a tablet or the TV as a pre-bedtime balm, strongly consider rejiggering you routine so that your bub gets their Ms. Rachel fix in the morning instead.


More On Your Family’s Sleep



  • National Sleep Foundation: Good Light, Bad Light, and Better Sleep
  • Sleep Foundation: Light and Sleep
  • Cleveland Clinic: The Case for Wearing a Sleep Mask
  • Preliminary evidence that light through the eyelids can suppress melatonin and phase shift dim light melatonin onset. BMC Research Notes. May 2012
  • Wearing an eye mask during overnight sleep improves episodic learning and alertness. Sleep. March 2023
  • Cleveland Clinic: Why Light at Night Can Interfere With Your Sleep
  • The inner clock-Blue light sets the human rhythm. Journal of Biophotonics. December 2019
  • High Sensitivity of the Human Circadian Melatonin Rhythm to Resetting by Short Wavelength Light. The Journal of Clinical Endocrinology & Metabolism. September 2003
  • Home Lighting Before Usual Bedtime Impacts Circadian Timing: A Field Study. Photochemistry and Photobiology. May 2015
  • Michigan Medicine, University of Michigan: How to Use Bedroom Lighting to Improve Sleep Quality
  • Effects of light on human circadian rhythms, sleep and mood. Somnologie. August 2019
  • National Sleep Foundation's 2023 Sleep in America Poll: The Nation’s Sleep Health is Strongly Associated With the Nation’s Mental Health
  • Sleep Foundation: How Blue Light Affects Kids’ Sleep
  • Increased Sensitivity of the Circadian System to Light in Early/Mid-Puberty. The Journal of Clinical Endocrinology & Metabolism. November 2015
  • University of Boulder: How bright light keeps preschoolers wired at night

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Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.