How Light Therapy Can Improve Your Sleep

Sweet dreams.

by Natalia Lusinski
light therapy sleep benefits

When it comes to getting quality sleep, you probably have heard all the tips and tricks: limit blue light devices, don’t exercise too close to bedtime, and try to go to bed at the same time every night. But if insomnia is still an issue, light therapy can improve your sleep. Neuroscientist Dr. Chelsie Rohrschieb, lead sleep specialist at sleep management platform Wesper.co says using light therapy is another great way to strengthen and regulate your circadian rhythm. “It can be extremely good for sleep quality, health, and well-being,” she tells TZR in an email. “People who have insomnia or poor sleep [patterns] are especially susceptible to circadian dysfunction, so they need to be consistent with their light therapy.”

Regarding sleep and wakefulness, she says both are controlled by two systems in the brain. “The first is our sleep homeostatic function, which detects how much sleep debt we build up during the day, and the second is our circadian rhythm, our 24-hour biological clock, which tells us what time of day to be awake and asleep,” she explains. “While our circadian rhythm is controlled by a handful of genes, it also relies heavily on cues from sunlight. Scientists recommend that we get plenty of sunlight in the first half of the day, especially in the mornings, to suppress melatonin and help the brain feel energized and awake.

Conversely, once nighttime rolls around, one should avoid too much artificial light from light bulbs, lamps, and electronics in order to allow their melatonin to reach the appropriate levels to signal to the brain that it's time for bed. Ahead, Rohrschieb and other sleep experts explain everything you’ve ever wanted to know about light therapy in relation to how it can help you sleep better.

Light Therapy How-Tos

Although formal light therapy consists of using a light box or trying dawn simulation therapy — more on that in a bit — Rohrschieb says you can (and should) first try increasing your amount of natural light sources. “During the day, you can eat breakfast outside, sit by a window while you work, or use jet lag glasses while you work,” she says. Amy Korn-Reavis, a sleep specialist coach for BetterUp, agrees, quipping that one needs about 30 minutes to two hours of light per day, based on how bright the natural light is. “On a cloudy day, the light is about 2,500 lux (level of brightness), and on a sunny day, it is about 10,000 lux,” she tells TZR in an email. “When we consider light therapy, going outside and spending 30 minutes in the bright sun, or two hours when it is cloudy, would be a good first step.”

And, at night leading up to bedtime, you want to focus on getting as little light as possible. “You can try things like dimming your lights about two hours beforehand, putting away all electronics with screens at least one hour in advance, wearing blue light blocking glasses, and using candlelight,” Rohrschieb says. “This way, you’re reprogramming your brain so it knows to be more awake in daylight and more sleepy once it’s dark.” But if this natural light therapy doesn’t do the trick, you can speak to your health care practitioner — or a sleep expert — about trying more formal light therapies.

How Formal Light Therapy Methods Work

Dr. Arpan Parikh, psychiatrist and senior director of clinical experience for Ro Mind, a digital mental health service treating anxiety and depression, says there are two types of formal light therapy. “The first type is likely the one most folks think about — formally, called bright white light therapy (phototherapy),” he tells TZR in an email. “This format of light therapy involves using a specific type of light box (usually emitting 2,500 to 10,000 lux of light) for specific durations of time (generally 30 minutes a day to start) in a particular way (with the box sitting 16 to 24 inches away from your face, not directly facing into the eyes).”

But don’t just go out and buy a light box. “It’s important to consult with your primary care doctor before using a light therapy device, as there are potential side effects associated with their use and the risks and benefits should be discussed,” he says. Your doctor can also determine whether it’s a viable option for you and how exactly to use it. If you get a box that’s 2,500 lux, for example, you’ll likely use it for one to two hours per day versus 45 to 60 minutes for a 5,000 lux light box. Medical professional will also help you choose what type of lights to get (cool-white fluorescent or full-spectrum ones) and the box should have an ultraviolet filter, too.

Another type of light therapy device one can explore is dawn simulation therapy. Dr. Parikh says this involves the use of a specific device (dawn simulator, emitting 250 lux of light) which works by shining increasingly bright light at a distance of about 36” from the pillow (normally set on a nightstand) while sleeping, with the timing set so that it hits peak brightness at the time one expects to wake up. “Both of these formats of light therapy have been shown to improve sleep quality,” he says.

In addition to light therapy, basic sleep best practices should be noted as well, including the aforementioned: going to bed and rising at the same time every day (weekends, too), not doing strenuous exercise too soon before bed, and not looking at electronics for at least an hour before bed. Sleep expert Dr. Jessee Dietch says the impact of light from screens and other light before bed is dramatically reduced if you are able to get sufficient bright light exposure during the day, so that should be a big focus. “However, it's also somewhat important to block or reduce bright light at key times, specifically when bedtime approaches,” she tells TZR in an email. “It's unrealistic for most folks to completely turn off screens before bed, and that's OK.”

Dr. Dietch adds that, generally, dimming the lights and turning down the brightness on screens should be a normal part of your wind-down routine, ideally starting one to two hours before your preferred bedtime. “You can use light cues in your house (for example, a Hatch Restore) to automatically start dimming at the recommended time and remind you to start your wind down,” she says. “Other folks can find benefit from wearing red- or orange-tinted sunglasses for a few hours before bed, especially if they are unable to dim the lights.”

Aside from helping you sleep better, light therapy can also benefit you if you suffer from mood disorders, Parikh explains. These include depression (such as major depressive disorder), anxiety disorder (such as generalized anxiety disorder), bipolar disorder, or seasonal affective disorder (SAD), which is triggered by a change in seasons, usually fall, when the weather gets cooler and the sky gets darker. “Patients suffering from these conditions might find some symptomatic relief of their sleep difficulties through the use of light therapy,” he says. Rohrschieb adds that light therapy can also be helpful for people with circadian rhythm disorders and shift workers, those who live in areas of the world with low sun exposure, people who travel across time zones frequently, and people who have difficulty waking up in the morning.

When To Seek Help For Sleep Conditions

Usually, you’ll know if you’re not well-rested: You may be irritable or know you’re not getting seven or more hours of sleep per night. But Rohrschieb says you can look for other indicators, too, including feeling chronically sleepy during the day (regardless of how much sleep you're getting); taking 30 minutes (or longer) to fall asleep several times a week; waking up several times each night; having high blood pressure; suffering from chronic illness; and/or not being able to stick to a sleep schedule. Dietch adds that if sleep problems are having an impact on your daytime functioning, it may be time to consult with an expert. “If you have trouble getting through your day without dozing off or feeling very fatigued — or notice that sleep impacts your mood, concentration, work, or school — these are signals that you might need help with your sleep,” she says. “You can start with your primary care physician, but you may need more extensive care from a neurologist, a sleep medicine physician, or a behavioral sleep expert (e.g., a psychologist), depending on the nature of your sleep problem.”