By Brandon Peters, MD
It is pretty normal to use an alarm clock to wake up. What is not as common, however, is for the clock to mimic a sunrise and wake you with a gradually increasing amount of light. How do the best sunrise alarm clocks make waking easier? Learn how a dawn simulation light works, why it might be preferable to an audible alarm, who benefits most from its use, and what alternatives exist that may help to enforce a circadian pattern, easing insomnia and making it easier to wake and get up.
What Is a Sunrise Alarm Clock?
A sunrise alarm clock, or dawn simulation light, is an artificial light source that is integrated into a standard digital clock. It is timed to gradually wake a person at a selected time. It does this by mimicking the steadily increasing light of sunrise, often over 30 to 40 minutes, but some models may allow the timer to be adjusted from 15 to 60 minutes.
These simulators may have a full-spectrum white or yellow LED lightbulb. The color spectrum, or color temperature (think of this as the “warmth”), of this light may vary slightly from one model to the next. Most are of modest intensity, often 100 to 300 lux, with less light than a standard light box.
There are a variety of models, most costing less than $25 to $100, including:
Philips Wake-Up Light HF3520
Philips HF3505
Philips Somneo HF3650
hOmeLabs Sunrise Alarm Clock
Mosche Sunrise Alarm Clock
INLIFE Wake Up Light Alarm Clock
NATPLUS Sunrise Alarm Clock
iHome Zenergy Bedside Sleep Therapy Machine
totobay
Sharp Sunrise Simulator
Lumie
The add-on features also vary widely from one product to the next. Many have the ability to adjust the light intensity, snooze features, and associated standard alarm sounds or music. There may be USB ports integrated for charging devices. Beyond encouraging a gradual awakening, some can even dim light gradually (a so-called sunset feature), making it feel more natural to fall asleep.
How Do Dawn Simulation Lights Work?
Dawn simulation lights can make it easier to wake, but how do these devices work? It is important to consider the natural patterns of light and darkness and how the circadian rhythm enforces optimal sleep and wakefulness.
Humans, like most animals, have evolved to sleep overnight during darkness. Light, conversely, has a waking effect on the brain and body. It suppresses melatonin and activates the circadian alerting signal. Light at the wrong time, like from a screen prior to bedtime, may make it hard to fall asleep and contribute to insomnia. In the morning, when incorporated into a sunrise alarm clock, it may make it easier to wake.
Light exerts this impact by traveling from the eyes via the optic nerves to an area of the brain that regulates the body’s circadian rhythm. This area of the brain, called the suprachiasmatic nucleus, lies in the hypothalamus. It is the master clock of the body. Without it, the patterns of sleep and wakefulness, metabolism, hormone release, cortisol levels, body temperature, and other processes would run amok.
Fortunately, light at the proper time may help us to sleep and feel better. Even artificial light, if appropriately timed, may enforce the normal patterns of our body that would exist if we slept in a perfectly natural environment. A gradual increase of light in the morning hours, even in the natural darkness present in winter months at northern latitudes, may reinforce a normal pattern of waking.
Why Is Light Better Than Sound?
The sudden, blaring sound of an alarm clock will definitely wake someone. However, this abrupt shift from sleep to wakefulness can be disorienting. If full wakefulness is not attained, the snooze button may be pressed and sleep may quickly resume. Short awakenings, such as those lasting less than 5 minutes, may go unremembered. If the alarm clock is simply turned off—or smashed into 1,000 pieces—trouble may ensue!
Light may wake a person more gently and more gradually. The transition from sleep to wakefulness is more orderly. This may help to relieve sleep inertia, that profound sense of sleepiness that is difficult to shake when first opening your eyes. It is something that feels more natural. The sky does not go from pitch black to glaring sunshine. As the sun creeps over the horizon, the amount of light hitting our eyes (even through closed eyelids) steadily increases. It may reach a threshold where it finally wakes us. This may make it less likely a person would want to hit snooze repeatedly and fall back asleep. Even the thought of it seems more pleasant.
Who Should Consider a Sunrise Alarm?
Although there are certain groups who may benefit more from using a sunrise alarm, scientific research suggests that many of us could yield positive health impacts.
There are a surprising number of important benefits from the use of dawn simulation lights. Research suggests it may:
Improve cardiac function and reduce the risk of heart attacks
Provide a boost to the brain’s function (in select cognitive domains)
Enhance performance in tasks done immediately after waking
Clearly there are certain conditions or groups of people who would likely enjoy the effects of a sunrise alarm even more. Consider these possibilities:
Night owls
Delayed sleep phase syndrome is a circadian disorder characterized by difficulty initiating sleep (insomnia) and profound morning sleepiness. It affects 10 percent of the population, usually starting in the teenage years. Most night owls feel naturally sleepy close to 2 a.m. and may not naturally wake until 10 a.m. The use of a dawn simulation light may make waking a little easier. In some cases, a light box may be more effective to reinforce an earlier circadian phase.
Winter depression
Seasonal affective disorder, or winter depression, impacts people living in northern latitudes during the winter months when the nights are long and the days are short. Darkness can make it hard to wake in the morning. This may lead to increased depressive symptoms, lethargy, prolonged sleep, weight gain, and other symptoms. An artificial light may help the morning to start a little easier.
Teenagers
As noted above, teenagers are susceptible to delayed sleep phase syndrome. As a general rule, teens are more likely to have a slight delay in sleep timing, even with a less profound shift in the pattern. This can make it hard for adolescents to fall asleep at a desirable time. It can also make it very difficult to wake them in the morning. This can lead to early morning fights with parents, tardiness, absenteeism, and other problems like car accidents, inattention, and academic failure. Consider how desirable it might be to have a gentle light do the waking, and let the drama of the morning fade away.
Shift workers
Those who work atypical shifts—second, third, graveyard, rotating, or even call coverage—are subject to many sleep problems. When the desire for sleep and wake is forcibly misaligned from the patterns of darkness and light, it can be difficult to function optimally. This may lead to increased errors, accidents, and health problems (including a higher risk for cardiovascular disease, weight gain, and breast and colorectal cancers). Artificial light, if properly timed, may help to alleviate some of this misalignment.
Jet lag
For every one time zone crossed, it can take one day to adjust the circadian rhythm. Traveling across a continent, or an ocean, can lead to significant disruption. The use of a sunrise alarm clock may make this transition easier. The optimal timing of this light exposure will depend on the distance traveled, and whether preparation was made prior to departing on the trip.
Hearing impaired
Finally, those with a hearing impairment may benefit from using a light to wake, rather than an audible alarm. The deaf may otherwise need to rely on others to wake on time. The use of a sunrise alarm clock may provide a new degree of independence.
Alternatives to Sunrise Alarm Clocks
Many people will be attracted to the possibility of easing insomnia and waking and getting up easier. Not everyone may want to use a sunrise alarm clock, however. There may be a handful of alternatives to consider. Consider how these additional options may make it easier to wake in the morning:
Natural sunlight
Throw the window shades open in your bedroom before retiring for the evening. This will let in natural light. After sunrise, the light will be able to stream through the windows and promote wakefulness. Unfortunately, this may not be ideally timed certain times of the year.
Light box
Consider a light box with 10,000 lux of intensity. It is powerful enough to shift the circadian rhythm, benefiting seasonal affective disorder as well.
Light therapy glasses
For those with a little extra buying power, light therapy glasses are a convenient and effective option. With a lower amount of light, shone directly into the eyes, these glasses can make it easier to wake.
Caffeine
A cup of coffee or tea can make it easier to get the morning started. Caffeine blocks adenosine, a signal for sleep, within the brain. With a half-life of 4 to 6 hours, it can get you through the morning.
Get motivated
Consider ways to motivate yourself out of bed. Morning exercise, quickly hopping in the shower, a special breakfast, or stepping outside to enjoy the early light may be helpful. In some cases, scheduling something you really enjoy for first thing in the morning may do the trick.
Conclusion
There are many effective ways to wake and feel refreshed. A sunrise alarm clock may help to ease the transition to wakefulness. If you consistently struggle to wake, or have sleep of poor quality, consider getting evaluate by a board-certified sleep physician. Sleep disorders can be effectively resolved to the benefit of your health and well-being.
Sources:
Follum JD, Catchpole JM. “Sunrise alarm clock for the hearing impaired.” Biomed Sci Instrum. 2011;47:18-23.
Viola AU et al. “Dawn simulation light: a potential cardiac events protector.” Sleep Med. 2015 Apr;16(4):457-61. doi: 10.1016/j.sleep.2014.12.016. Epub 2015 Feb 26.
Gabel V et al. “Dawn simulation light impacts on different cognitive domains under sleep restriction.” Behav Brain Res. 2015 Mar 15;281:258-66. doi: 10.1016/j.bbr.2014.12.043. Epub 2014 Dec 27.
Thompson A et al. “Effects of dawn simulation on markers of sleep inertia and post-waking performance in humans.” Eur J Appl Physiol. 2014 May;114(5):1049-56. doi: 10.1007/s00421-014.2831-z. Epub 2014 Feb 11.