What Is Insomnia Light Therapy? Here’s How It Works
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Light therapy may help certain sleep disorders, including insomnia. Here's what to know about its use in insomnia and how to try it.
Here’s a simple definition for insomnia: You can’t sleep when you want to sleep—and you’re distressed by it, says W. Chris Winter, MD, author of The Sleep Solution: Why Your Sleep is Broken and How to Fix It.
If you have a circadian rhythm disorder—your sleep-wake cycle is not aligned with your environment—you might have insomnia as a result of trying to go to bed when you’re not yet tired. For instance, you know you have to wake up at 8 a.m. for work. So you try to go to bed by midnight, even though you won’t be able to sleep until 2 or 3 a.m. As you lay awake, you grow increasingly agitated and worried that tomorrow you’ll be a wreck. (Here are some tips for insomnia for better sleep.)
That’s where light therapy—also known as bright light therapy, light exposure therapy, circadian light therapy, or photography—might help. When you need to adjust your bedtime, “light exposure at specific times can be instrumental in moving your [body] clock forward or backward,” Dr. Winter says.
Is it circadian rhythm disorder or insomnia?
To understand whether light therapy is best for you, it’s important to determine whether you have a circadian rhythm disorder or insomnia. Now, it is possible to have insomnia due to a circadian rhythm disorder (more on this later).
When it comes to insomnia, you’re likely to have sleep issues, such as problems falling asleep, staying asleep, or experiencing poor sleep quality. Chronic insomnia is when you experience any of these sleep issues several times a week for a period of three months or more.
Insomnia is a condition that has many causes. Risk factors include stress, intense emotional distress (like the death of a loved one), and an irregular schedule; medications, caffeine, and alcohol can also cause it, notes the U.S. National Library of Medicine.
Depending on the underlying cause of your insomnia, light therapy may or may not be useful.
(Learn more about the causes of insomnia.)
Circadian rhythm disorders
Circadian rhythm disorders refer to a group of sleep disorders that can develop randomly. Shift work, pregnancy, medications, mental health problems, and menopause are just some of the causes. People with circadian rhythm disorders will also experience difficulty falling asleep or staying sleep. In addition, they will also tend to wake up too early, but not be able to fall back asleep. Or they’ll get enough sleep, but still feel sleepy.
(Here’s why you wake up before your alarm clock.)
Not sure if your insomnia is due to a circadian rhythm disorder or something else? Then Dr. Winter suggests asking yourself this question: “If I won the lottery and wasn’t beholden to a specific schedule, would I still have a sleep problem?” If the answer is no, then your issue might be a circadian rhythm disorder. But if you’d answer that with a “yes” because worries keep you up at night, then you may benefit from other insomnia treatments, such as cognitive-behavioral therapy for insomnia.
The value of light therapy
Light can be powerful medicine. “Light therapy works by addressing a problem in the circadian system,” says Ari Shechter, assistant professor of medical sciences at Columbia University Medical Center in New York City. Traditionally, if you have a circadian rhythm disorder that’s contributing to insomnia and you want to be able to go to bed earlier, then light therapy would be given in the morning, right after you wake up. This would advance your circadian system, making it easier to fall asleep earlier, he explains.
(Here’s what your sleep habits are trying to tell you.)
However, it’s also possible that you don’t have a circadian rhythm disorder. It may instead be something in your lifestyle that is delaying your body clock. Most often, says Shechter, that’s the blue light from exposure to electronic devices at night. This blue light is activating and can make it harder for you to fall asleep. In this case, you’re using light at the wrong time, which results in sleeplessness.
(Is there a connection between blue light and digital eye strain?)
How light therapy works
Light therapy treatment works by using a special light box or visor designed for light therapy. This light will resemble light that is similar to outside, but without the ultraviolet rays. In a session, you typically sit in front of your light source for 20 to 30 minutes, several times a day.
The light intensity of a light box should be about 10,000 lux and kept between 16 to 24 inches away from your face, suggests a study in the Journal of Psychiatry and Neuroscience. The light should shine directly into your eyes.
The light exposure works by reprograming your sleep-wake cycle by delaying the production of melatonin and promoting the production of serotonin. Melatonin levels increase when it’s dark while serotonin levels increase when there’s light. These two chemicals regulate your sleep-wake cycle.
This means you’ll start to feel more alert during the day as serotonin increases and feel more tired at night as melatonin ramps up.
Why light therapy may work for insomnia
In a review of studies, published in 2016 in Sleep Medicine Reviews, researchers found that bright light therapy was able to treat sleep problems in general, as well as circadian rhythm disorders and insomnia. As Shechter points out, bright light therapy improved some circadian markers, like the onset of melatonin, which can be associated with an easier time falling asleep.
(Here’s what you need to know about taking melatonin for sleep.)
More than that, bright light therapy also alleviates lethargy and fatigue. “Getting light in the morning as you start your day could promote a more physically active day,” Shechter says. “And starting your day in a more alert and active way may have the downstream effect of improving your sleep at night.”
One symptom of insomnia is waking up feeling unrefreshed, which manifests as lingering grogginess throughout the day, adds Shechter. Lack of sleep also tanks your mood. With morning bright light therapy, bonus potential benefits include alertness, energy, and a better mood, alleviating the daytime “blahs” that comes with insomnia.
(Here’s what happens when you don’t get enough sleep.)
How to try light therapy for insomnia
If your issue is that you cannot fall asleep at night, then you will want to get light exposure in the morning. “Natural sunlight for 30 minutes after you wake up is ideal,” says Shechter. Direct sunlight provides the most powerful source of full-spectrum light.
If that’s not possible due to the time of year, where you live, or your schedule, then consider an artificial light box or device. (Here’s what happened when someone tried light-box therapy for seasonal affective disorder.)
Bright light therapy is pretty safe, but you still want to discuss it with your doctor first, says Shechter. Certain mood disorders, eye disorders and diseases, migraine conditions, and medications that make you more photosensitive may mean that bright light is not appropriate for you.
Light therapy at home
When you’re going to use light, you have options and can even do it at home. Purchasing a light box (look for one that’s about 10,000 lux) is one option. But there is also a new category of wearables that can make light therapy even more convenient, says Shechter. “I like wearables because you can engage in your morning routine when wearing them, unlike a light box that you need to sit next to,” he says. That simplicity and convenience can make it more likely that you’ll actually use the device and stick with it.
Dr. Winter agrees, pointing to the AYO wearable ($199), which looks like a combination of glasses and a visor. It connects to an app via Bluetooth. With app connectivity, the device can help you determine when you should use the device and for how long, taking the guesswork out of treatment.
Other ways to adjust your body clock with insomnia
It’s not just about using a light therapy lamp or box, or putting on a wearable. There are several factors that can regulate your body clock. And by regulating your body clock, you can make it easier to go to sleep at your intended bedtime so you can get the rest you need. That includes waking up at a consistent time every morning, exercising or going out for a walk in the morning, and eating meals at the same time each day, Dr. Winter advises.
If nighttime light is exacerbating problems falling asleep, you’ll want to employ a sort of reverse light therapy to nighttime, says Shechter. That means exposing yourself to bright light during the day as well as dimming or beginning to turn the lights off in your home at night. Stay off of your devices before bed so you can avoid the blue light that stops you from dozing off.
Next, try the best remedies for insomnia.
- W. Chris Winter, MD, author of The Sleep Solution: Why Your Sleep is Broken and How to Fix It, and sleep medicine expert in Charlottesville, Virginia
- National Heart, Lung, and Blood Institute: "Circadian Rhythm Disorders"
- Ari Shechter, PhD, assistant professor of medical sciences at Columbia University Medical Center in New York City
- U.S. National Library of Medicine: "Insomnia"
- Sleep Medicine Reviews: "The effects of light therapy on sleep problems: A systematic review and meta-analysis"
- Journal of Psychiatry and Neuroscience: "What is the optimal implementation of bright light therapy for seasonal affective disorder (SAD)?"