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Sleep and mental health are two peas in a pod. You can’t have one without the other. Entire industries have popped up in trying to help improve our sleep hygiene. Many different factors determine how well we are resting, not the least of which is the complicated relationship between light and sleep.
Okay, I know I’m not blowing any minds here. There being a connection between the sleep and light is probably a no-brainer. What you may not know is why, or how deep that relationship runs.
The Science of Light and Sleep
In simple terms, our bodies know it’s time to go to sleep when it’s dark. That darkness cues our brains to produce melatonin. You might’ve seen or taken a supplement of melatonin from the pharmacy. It’s a sleep hormone that’s essential for falling and staying asleep.
Just as darkness helps us get to sleep, light resets our inner clock, also called the circadian rhythm. Since we don’t have digital clocks embedded in our arms (yet), our bodies have to guesstimate whether it’s time to be active or conk out in bed. Our circadian rhythm isn’t perfect either, typically acting as if the day is 23-25 hours. Light syncs our inner clocks with the day.
On the other hand, light can overstay its welcome. Thanks to technology, we’re exposed to light at all times of the day. While we’re in bed scrolling on our phones with the TV on in front of us, the light tricks our brains so it thinks it’s daytime and thus doesn’t need to make melatonin. It becomes harder to enter that sweet slumber.
Obviously, I’m simplifying the process a bit. If you’re interested in the complete scientific breakdown, check out this great research article.
People have different sensitivities to light, but this science is sound. In fact, there is more and more effort in trying to use “light therapy” to treat mental health conditions. Think about seasonal affective disorder, when a person experiences sadness that cycles with the season. Light therapy may treat a depressed person in the dead of winter and help their inner clocks sync up while perking up their moods. Light therapy may also be helpful for diseases like schizophrenia, dementia, and ADHD, but this treatment approach is still pretty new.
Some Light Habits
Now that you know the basics about sleep and light, let’s talk application. Researchers have found each of the following suggestions can improve a person’s sleep.
Feel free to experiment and give each of these a try. Remember, there’s no one-size-fits-all strategy here.
It’s Curtains for You
Is the sun rising while you’re still catching Zs? If so, your body is already absorbing that light and starting to prepare to wake up. This isn’t always a bad thing. In fact, the sun makes an excellent alarm clock for some sensitive people. If you’re trying to sleep in, though, you may want curtains or a window shade to rest longer. This is even more important if you have streetlamps or other lights outside your windows that can throw get in the way of your manufacturing melatonin at night.
Make sure the coverings fit well with the window. Slivers of light on you throughout the night aren’t great.
Light Will Boost Your Sleep-Wake Cycle
A nice early walk doesn’t just burn calories. Catching some sun in the morning will help sync up your circadian rhythm. Put another way, it’s like setting the clock in your body so it knows when to sleep later on.
Natural light can help keep you awake throughout the day, too. Artificial light is helpful and often the only option, of course, but side effects like eyestrain can be a bugger. For one, many bulbs, like LEDs, use blue light. More on that in a bit.
Consider arranging your house as best as you can to take advantage of the sunlight. Windows on the east and west sides can catch the sun as it rises and sets, though be careful, that can make your home much hotter.
Dim the Lights
Our bodies’ circadian rhythms are most susceptible to light at night. During the hour before you need to sleep, try dimming the lights so your body can start on sleep’s natural processes. If you don’t have a dimmer, turn off or limit the lights around you.
If dimming isn’t an option or a difference-maker in your sleep, it may be worth installing a dim red wavelength lightbulb in a lamp by your bed. Red light is the longest wavelength and gives out the lowest energy, meaning your body will be least affected by this type of light.
Get Rid of Extra Light at Night
As mentioned above, darkness is critical for creating melatonin and enjoying a deep, restful sleep. When you’re ready to sleep, search out all the extraneous light and turn them off. This means limiting the use of overly bright alarm clocks and even clearing off the flashing light your phone gives for notifications.
I realize this sounds minor, but light exposure adds up more quickly than you’d think.
Blue Light, Be Gone!
Blue light from the sun is a super powerful, short wavelength that carries a ton of energy. That energy can be helpful– research shows blue light improves our mental sharpness. It also sets our circadian rhythm better than any other light. Absorbing blue light into the afternoon and evening can trick our bodies into thinking it’s earlier than it is. Goodbye, melatonin.
Back in the caveman days, blue light only came from the sun. Now it’s everywhere. Television, computer, and phone screens each use blue light. This makes image quality pop, but this nonstop flood of blue light from devices comes at a cost. With these bursts of light energy bombarding our bodies well into the night, our bodies struggle syncing right. Circadian chaos is unleashed.
Do your part and limit the blue light coming from your devices. Consider turning on your phone’s blue light filter. And while the timing isn’t universally agreed upon, experts generally agree that you should turn off your devices between half an hour to an hour before going to sleep.
Mask Up
We can’t control everything, and sometimes a smattering of light is unavoidable. There may be a blazing streetlamp by your window, a crucial night light in the hallway, or a night owl bed-mate on their computer next to you. If you’ve tried everything possible and light still bothers you, consider using an eye mask.
Light and Sleep: The Bottom Line
In my experience, people usually underrate how much light affects our sleep quality. As outlined above, getting the right light and the right times makes a world of difference. Play to your chemistry and follow these tips, and you may find your sleep finally enjoying restful, restorative sleep.
Of course, light is just one consideration here. If you’re interested, check out this guide I put together covering all eleven elements to good sleep hygiene.
I love talking about all subjects related to mental health. If you want more of this type of content, please subscribe to my email list on the side bar. When you do, you’ll receive a free worksheet to track your sleep. Learn what is and isn’t helping your sleeping patterns.
What role do you think light plays in your sleep? Let me know in the comments below!
