Have you ever wondered why some nights, no matter how tired you feel, sleep just doesn’t come easily? Or why you find yourself wide awake at odd hours, struggling to drift off again? The answer could lie in an often-overlooked factor: your exposure to light and darkness.
Light plays a crucial role in regulating your body’s internal clock, or circadian rhythm. From the brightness of the morning sun to the glow of your bedside lamp, every type of light sends signals to your brain that influence when you feel awake and when you’re ready to sleep. Understanding how to use light and darkness to your advantage is one of the most powerful tools for improving your sleep naturally.
In this blog, we’ll explore why light matters so much for your sleep and exactly how you can work with it to feel more rested and refreshed. From when to soak up bright light to when to dim the lights, we’ll break down actionable strategies to help you sleep better. Plus, we’ll tackle the topic of blue light—how it affects your sleep and whether blue light-blocking glasses are worth the hype.
Why light and darkness matter for your sleep
It makes sense that light and darkness matter when it comes to sleep. After all, most of us turn the lights off at night when we sleep and then are exposed to light all day while we’re awake. It’s something that we all intuitively understand about the world and the way our bodies work. But there’s a whole lot more to it than you probably ever realized.
If you’ve heard of the term “circadian rhythm,” you probably know it has to do with your sleep. The circadian rhythm is the natural cycle of physical, mental, and behavioural changes that the body goes through in a 24-hour cycle, including but not limited to sleep! The term literally means “about a day.” You may also see the term circadian rhythm referred to as your body clock, biological clock, or internal clock. All three would be accurate.
We could go into the nitty gritty of all the functions of your circadian rhythm, how your hormones play a role, and what specific parts of the brain do what jobs in this process, but I will spare you the science lesson. The two big things you need to understand are:
Bright light during the day tells your body that it’s time to be awake and alert.
Darkness at night signals to your brain that it’s time to rest and release melatonin—the sleep hormone.
Seems pretty simple, right? And the sun does this for us anyway, so what’s the big problem? Our bodies are really good at naturally keeping our circadian rhythms aligned. However, the introduction of artificial light (aka not the sun) can have negative effects on our sleep. Light and darkness are powerful cues for our circadian rhythm, but too much light at the wrong time can confuse your body clock, making it really hard to fall asleep and stay asleep.
When to get bright light
Bright light is especially helpful in the morning: If you’re struggling with your sleep, it’s always a good idea to expose yourself to sunlight first thing in the morning. Ideally, this should happen within the first 60 minutes of waking up. The earlier, the better though! By exposing yourself to sunlight first thing, you are “waking up” your body clock and helping it to stay on track. Best of all, by exposing yourself to the morning sun/ sun lamp, you will FEEL more alert!
Some easy ways to get that morning sunlight include taking your dog for a quick walk outside or enjoying coffee on your front steps. Aim for roughly 5-10 minutes on a sunny day. If it’s a cloudy day, the sunlight that filters through the clouds is still better than nothing! On cloudy days, aim for a bit longer, roughly 10-20 minutes.
If you often have to be up and start your day before the sun is up, then I’d highly recommend looking into a sunlamp. This is something you can easily purchase and set up in your home. You can leave it on your night stand and turn it on first thing (this is what I do!) or use it while you eat your breakfast. When you purchase a sunlamp, just make sure that it is 10,000 lux and try to sit in front of it for 10-20 minutes in the morning. I recommend this particular sunlamp.
Bright light is also key throughout the rest of the day: Since light is the main signal telling your body it is time to be awake and alert, it’s not only important to have exposure in the morning but also all through the day. Natural light throughout your day helps to keep your energy levels up and keeps your body feeling awake. If you can schedule even just short bursts of time to get outside or sit near a window and get a “sun break” it will do wonders for your circadian rhythm.
When to turn the lights down
As we near bedtime, we want to start reducing the light around us and increasing darkness so our body is ready to sleep at bedtime.
You should dim lights in the evening: Ideally about 2-3 hours before you’d like to be settling to sleep is when you should start dimming lights in your home. Turn off all extra lights and try to make do with as few house lights on as possible. Aim for warm, soft lighting and lamps instead of overhead lights. If you have especially harsh lights, consider using a dimmer. Keeping bright lights on in the evening can make it harder for your brain to wind down prior to bedtime.
Screens should be turned off 1 hour before bed: I know this can be a hard one, but TVs, phones, and computers should be avoided for the hour before bedtime. These screens give off blue light and they can trick your circadian rhythm into thinking it’s still daytime. Instead of spending your last hour of the day on screens, try relaxing with a book (using soft, dim light of course), listening to music, doing some light stretching or yoga.
Why is blue light so bad at night? As mentioned above, blue light essentially tricks your brain into thinking it is daytime. As you near bedtime, the last thing you want is to feel tired but have your internal clock confused about what time it actually is. Blue light exposure close to bedtime will stop your body from making melatonin (our sleep hormone) and that will significantly delay your ability to fall asleep. Also, if you struggle with falling asleep and often find yourself turning to your phone to pass the time, you are likely making the situation even worse for yourself.
What about blue light-blocking glasses? There are special glasses you can purchase that help to block blue light. They will have amber or red lenses to cancel out the blue light coming from your screens. If you use these glasses, they should be used for 1-2 hours before bed and kept on anytime you are around a screen. Because these glasses block the blue light, it keeps your brain from being tricked into thinking it’s still daytime so you can get to sleep easier at bedtime. But buyer beware- some glasses marketed as blue light blocking are not actually blue light. Pay attention to the lenses and ensure they are red or amber tinted. If they are just clear lenses then they are only good for alleviating eye strain, not necessarily blocking blue light.
It should be dark while sleeping (or while you wish you were sleeping): Depending on your environment and where you live, it can take a little extra work to get your room dark all night but it will be worth your efforts. Make sure your bedroom is as DARK as possible.
You may need to get creative and cover up lights from clocks or chargers. You’ll want to hang blackout curtains in your room to block any outside light from creeping in. If you have a lot of light coming into your room you may opt for a sleep mask instead. These can be great because they’re easy to grab and go for travel too.
Small steps you can start today
Get morning sunlight within 60 minutes of starting your day
Aim for several sun breaks throughout the daytime
Dim lights 2-3 hours before bed
Wear blue light-blocking glass (i.e. amber or red lens) 1-3 hours before bed.
Shut down screens an hour before you sleep
Turn your room into a dark and cozy cave-like environment
In conclusion
Understanding the influence of light and darkness on your sleep is a game changer. By intentionally managing your exposure to bright light during the day and dimming the lights as bedtime approaches, you can work with your body’s natural rhythms to start sleeping better. Sleep doesn’t need to be super complicated—it’s about making small, thoughtful adjustments that align your environment with your body’s needs. Remember, if you’re struggling with sleep, prioritizing your relationship to light and dark is always worth the effort.
If you’re ready to transform your sleep and take a deeper dive into strategies tailored to your unique challenges, I’d love to help. Book a free discovery call with me today, and let’s work together to create a sleep plan that leaves you feeling refreshed and ready to tackle your days!