The Science Behind Sunrise Clocks

By Kealia Reynolds

Sunrise clocks, also known as wake-up lights or dawn simulators, help wake sleepers with a simulated sunrise instead of a loud alarm. By slowly increasing the intensity and brightness of light in a dark room, sunrise clocks can advance the biological clock of a person who has an unbalanced circadian rhythm, allowing them to wake up more easily and experience better and longer sleep cycles.

The science behind sunrise clocks

To understand how sunrise clocks work, it’s important to understand the relationship between your biological clock and circadian rhythms. A biological clock is an innate timing mechanism that produces circadian rhythms and regulates their timing. Circadian rhythms are physical, mental, and behavioral changes that influence sleep-wake cycles. Biological clocks that run fast or slow can result in disrupted or abnormal circadian rhythms, which have been linked to various chronic health conditions such as sleep disorders, obesity, diabetes, depression, bipolar disorder, and seasonal affective disorder (SAD).

For people who have difficulty regulating their sleep-wake cycles or have a complex health condition like SAD, sunrise clocks can create the foundation needed to get the seven to nine hours of sleep that the average adult needs for proper cognitive functioning. The theory behind this is that exposure to the right kind of light can speed up the waking-up process and help people comfortably start their daily routine.

According to Arthur Smith, lead editor at, “If you have a strong sense of your circadian rhythm, you will have no problem waking up at the same time each morning without the help of an alarm. But if you are like most people, setting an alarm to wake you up in the morning is a must. However, regular alarms, although efficient at waking you up, don’t guarantee that you will feel good or even particularly awake when they go off.” That’s where sunrise clocks come in.

According to Smith, “By imitating sunrise, wake-up light clocks help to keep your sleep/wake cycle and all the hormones and chemicals in your body that come with it in check, and therefore help you wake up easier each morning. And that’s because our bodies are naturally programmed to wake up when the sun rises.”

But do sunrise clocks actually work?

According to Dr. Ari Shechter, assistant professor of Medical Sciences at Columbia University’s Irving Medical Center, some commercially available sunrise clocks might not have necessarily undergone controlled clinical testing and evaluation, so it’s hard to determine whether all sunrise clocks work.

“However, from clinical trials, it does appear that these types of dawn simulators can be useful for facilitating the waking up process,” says Dr. Shechter. “In laboratory-based controlled studies, devices that produce a naturalistic dawn simulation (i.e. gradually increasing light levels starting from before awakening to mimic the natural sunrise) have been shown to reduce feelings of sleepiness and increase feelings of alertness after awakening, and improve mood, particularly in individuals with seasonal affective disorder.”

Who can benefit from sunrise clocks?

According to Dr. Shechter, naturalistic dawn simulation can be useful for people who have a hard time waking up in the morning, for those who are waking up while it’s still dark outside or use blackout curtains in their bedroom, and especially for those with SAD.

People with SAD typically experience difficulty falling asleep and waking up, leading to internal biological clock disruptions. This can cause depression and mood swings that last until the seasons change. Sunrise clocks may relieve this type of depression by artificially lengthening the day, making the body believe it’s a sunny summer day when dawn occurs at an earlier hour (like in the fall or winter).

Key factors to consider before buying a sunrise clock

  • Amount of light—The optimal light level for a dawn simulator is 10,000 lux. Lux refers to how much light gets to the eye: the higher the number, the more light reaches the eye.
  • Color temperature—The average color temperature of dawn simulators ranges between 4000 and 6500 Kelvins. To match the sun’s approximate color temperature, consider buying a sunrise clock that is around 5600K.
  • Distance from light—To get the best results from your wake-up light, you’ll want to place it near your bed on a nightstand or table at pillow-level.
  • Flicker-free lights—When shopping around for a sunrise clock, look for one that doesn’t flicker. Lights that have a noticeable flicker can be problematic for individuals with photosensitive epilepsy and can cause vertigo, tinnitus, migraines, and dizziness. Even those who haven’t been diagnosed with epilepsy in the past can be affected by flickering artificial light and experience seizures or dizziness.

Let's Keep This Going


Sleeping Advice for Those With Lower Back Pain

Doctor Patricia Carter, PhD, RN, CNS, at the University of Texas at Austin School of Nursing provides sleep advice for those who wake up with back pain and for those who experience lower back pain before falling asleep.

Read More

The Best Morning Routine for Your Health: A Medical Opinion

Set up your days for success by ensuring your morning routine is as healthful as possible. From sleep and exercise habits to meals and meditation, here’s a doctor’s opinion on crafting the best morning routine for your health.

Read More

How to Use Your iPhone to Get Better Sleep

We explore three tools you can use with you iPhone that can help you fall asleep more quickly, sleep longer and get better, more restful sleep when you do hit the hay.

Read More

Sleeping on the Floor:
A Medical Opinion

Medical professionals and Paleo enthusiasts have conflicting opinions when it comes to the benefits of sleeping on the floor. To get to the bottom of this debate, we talked to a resident expert on sleep and back pain clinical director and compared the pros and cons of this sleep preference.

Read More
Peaceful man sleeping in bed at home in the bedroom

Which Sleeping Position
Is Best For You?

Ever wondered if there is a best sleeping position for you? Dr. Eric Gish, DO, Associate Dean of Osteopathic Manipulative Medicine Integration & Associate Professor at Campbell University School of Osteopathic Medicine, weighs in.

Read More
Bedroom Products

Best Mattresses For Stomach Sleepers

Check out House Method’s favorite mattresses for stomach sleepers. Stomach sleepers look no further, we’ve outlined all the best mattress options to provide the best stomach sleeping comfort.

Read More

The Basics of Baby Sleep: What to Expect During the First Year

New babies bring serious joy, but they can also bring serious sleep woes. Knowing what to expect when it comes to baby sleep—as well as a few strategies—can make the difference between sleep deprivation and sweet dreams. From self-soothing to sleep training and how parents can get some rest too, here’s what you need to know.

Read More

How to Get Great Sleep While Traveling: Pack a Mini Sound Machine

We took the Marpac Rohm travel sound machine on a trip to a busy Chicago hotel and put it to the test. Here's how the powerful little machine fared against 24/7 elevator noise.

Read More
Bedroom Accessories

The Best White Noise Machine
for Ugly Sleep

We tested the Marpac Dohm white noise machine to see if we could finally get that drooling, lines-on-the-face kind of deep sleep. Basically, we wanted to wake up looking like we had been in a Whitesnake video.

Read More

By continuing to browse or by clicking “OK” you agree to the storing of first- and third-party cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Privacy Policy.