Locations:
Search IconSearch
August 22, 2024/Living Healthy/Sleep

Here’s Why Total Darkness Can Help You Sleep Better

If you’ve been sleeping with artificial light, it may be affecting your circadian rhythm and suppressing your melatonin

Person sleeping in darkness, light off

How many times have you gotten cranky when your partner has the reading light on next to you in bed, or when sunlight is streaming through the windows when you’re trying to fall asleep?

Advertisement

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

Many things can impact our ability to sleep. “Caffeine, noisy sleep environments and restless bed partners (including pets) are frequently recognized as disruptors of sleep, but light can negatively affect our sleep as well,” says sleep disorders specialist Christen Cheuvront, MSN, APRN-CNP.

Here’s what you need to know about the link between sleep and light.

Importance of sleep

First, let’s go over why sleep is so important in the first place. And why even a seemingly small annoyance — like a light — can impact your sleep and overall health more than you may think.

Imagine your body is like a superhero, and sleep is its secret power. Depending on your age, you probably need about seven to eight hours of sleep a night at a minimum. Your sleep quantity and quality affect a tremendous amount of your body’s functions, including:

  • Energy levels.
  • Mood and memory.
  • Heart health.
  • Weight gain.
  • Stress levels.

A lack of quality sleep is associated with everything from sleep deprivation, high blood pressure and diabetes to obesity and depression. Getting enough sleep really is one of the most important aspects of healthy living.

How keeping the lights on affects sleep

Light stimulates your brain, making it more alert. If there’s light in your bedroom — even if your eyes are closed — it can still impact your sleep by preventing your brain from fully entering the deep and restorative stages of sleep.

Advertisement

A 2016 study looked at the amount of light people were exposed to at night. The researchers found that those who had light exposure while sleeping got about 10 minutes less sleep per night. They also were more likely to report fatigue, wake up confused during the night, and have excessive sleepiness and impaired functioning during the day.

Although the study doesn’t prove cause and effect, the researchers believe that intense outdoor illumination in the evening affects sleep quality. Those who lived in cities with a population of 500,000 or more were exposed to street lights three to six times more intensely than those who lived in lesser-populated areas. And people with high nighttime light exposure, for example, were more likely than those in low-lit regions of the country to be dissatisfied with their sleep quantity or quality.

So, why does light (or lack of it) seem to have such a significant impact on our sleep? Here’s how artificial light may affect your ZZZs:

Suppresses your melatonin

When it’s dark, your brain produces a sleep-promoting hormone called melatonin, which helps you feel sleepy and regulates your sleep-wake cycle. Your levels of melatonin naturally rise in the evening, but exposure to light delays the release of that hormone.

This is especially true for bright lights and blue light from screens and certain bulbs, which can make it even harder for you to fall asleep.

Disrupts your circadian rhythm

Your body has a natural internal clock called the circadian rhythm that helps regulate your sleep-wake cycles. Light is a powerful signal for directing those cycles on and off, like a switch.

“Our brain is signaled by light to activate other organs in the body, which control metabolism, digestion and immune function,” says Cheuvront. “Light exposure essentially causes a trickle-down effect that influences the timing of these bodily functions. When we are exposed to light during sleep, our circadian rhythm becomes disrupted.”

We take cues from the intensity and timing of light to help us sleep and wake up. Sleeping with lights on, especially if they’re bright, can confuse your body’s internal clock and disrupt your natural sleep patterns.

How to avoid light at bedtime

If you live near bright street lights, it’s a good idea to take some preventive measures. Some ways to avoid light disruptions while falling asleep include:

  • Use blackout shades or drapes.
  • Wear an eye mask.
  • Cover your phone and other electronics.
  • Minimize light from alarm clocks.
  • Use nightlights in hallways and bathrooms rather than leaving lights on.

Advertisement

“Blackout curtains and eye masks are great tools, especially for night shift workers,” reiterates Cheuvront. “When shift workers need to sleep during the day, it can be challenging if sunlight is streaming in through the windows.” 

Other potential sleep disruptors

Another big source of sleep disturbance that ties in with light exposure is our screens. Yes, your phone is a form of light, too. And a sinister one before bed.

If you’re the type of person who loves to scroll through your social media or watch videos on your smartphone before dozing off, it’s a good time to kick this habit. Smartphones give off a blue light that mimics daylight, which, in turn, prevents you from falling asleep promptly.

Try to adjust your evening tendencies by cutting off your screen time one hour before bed (this includes TVs, too!). It might be a hard adjustment at first, but take note of how much this impacts the quality of your sleep!

The bottom line

Having the best environment for falling asleep can make a big impact on your sleep quality. You want your space to feel calming and serene in every way so your brain knows when it’s time to hit the hay.

Light exposure affects our circadian rhythm and melatonin production, so try cutting down on how much light bursts into your room at night. If you’re still having trouble falling asleep, talk to a healthcare provider for guidance.

Advertisement

Learn more about our editorial process.

Related Articles

Baby sleeping on back in crib at night, with mobile
January 21, 2025/Children's Health
When and How To Sleep Train Your Baby

You can choose one method or combine aspects from a few to help your baby learn to sleep through the night

Person in bed at night, reading, warm beverage on nightstand, oversized clock and relaxing pre-bed ideas floating around
January 17, 2025/Sleep
How To Fix Your Sleep Schedule

A regular sleep schedule is essential to your well-being — be consistent and take time to wind down

Person sitting on edge of bed with hand on lower back, arched in discomfort
January 15, 2025/Chronic Pain
Why Your Lower Back Pain Is Worse in the Morning (and What To Do About It)

Your sleep position, immobility, mattress and underlying conditions can all cause morning back pain

Person lying on back, hands folded against chest, sleeping in bright daylit room
January 7, 2025/Sleep
What’s the Best Sleep Position for You?

There’s no one sleep position that’s best for everyone — but you may benefit from sleeping a certain way depending on your individual needs

Person in bed sleeping on their side, covers off
January 3, 2025/Sleep
Breathing Problems? Try These Sleep Positions

If you’re feeling short of breath, sleep can be tough — propping yourself up or sleeping on your side may help

Tan tablets pouring from bottle into a hand
December 24, 2024/Sleep
Does Magnesium Help You Sleep Better?

Research is limited on whether the supplement can help you snooze, and there may be better options

person sitting down, holding their hand to their throat
December 18, 2024/Ear, Nose & Throat
Why You Have a Sore Throat in the Morning

Dry air and acid reflux are just two of the many possible causes of your scratchy throat

Female asleep in bed in darkened bedroom, red alarm clock on table
November 15, 2024/Sleep
Why Women Need To Sleep More Than Men

Changing hormones, mental health issues and a higher risk for sleep disorders can all impact women’s sleep needs

Trending Topics

Person in bed sleeping on their side, covers off
Breathing Problems? Try These Sleep Positions

If you’re feeling short of breath, sleep can be tough — propping yourself up or sleeping on your side may help

A couple looking at skyline, with one person slightly behind the other, head bent down
What Is Anxious Attachment Style — and Do You Have It?

If you fear the unknown or find yourself needing reassurance often, you may identify with this attachment style

Glasses and bottle of yellow-colored prebiotic soda, with mint, lemon and ginger garnish
Are Prebiotic Sodas Good for You?

If you’re looking to boost your gut health, it’s better to get fiber from whole foods

Ad