How Light May Be Affecting Your Sleep

If you’ve been struggling to fall asleep, waking up in the middle of the night, or waking up feeling like you barely slept, there’s one thing I’d look at that often gets overlooked:

Light.

I’ve struggled with sleep for years, and changing my light environment has made a bigger difference for me than I expected. We tend to think about sleep in terms of supplements, magnesium, melatonin, meditation, or what time we get into bed. All of those things can have their place, but there’s something happening much earlier in the day (and throughout the evening) that your body is paying attention to the entire time.

Light is one of the main signals that sets your circadian rhythm.

Your body is constantly taking cues from your environment to figure out: Is it daytime? Is it time to be alert? Is it time to wind down? Is it time to sleep?

For most of human history, our days were naturally bright and our nights were naturally dark. Once the sun went down, there wasn't much competing with that darkness besides firelight. Today, we can have bright indoor lighting, TVs, phones, laptops and other sources of artificial light around us for hours after sunset. Our environment has changed dramatically. Our biology hasn't changed nearly as quickly.

So if your sleep feels off, it may be worth looking beyond your bedtime routine and asking a bigger question:

What signals am I giving my body throughout the day, especially after the sun goes down?

Let's look at what light has to do with your circadian rhythm, sleep, energy and overall health, and some simple things you can start changing right away.

The Missing Piece of the Sleep Puzzle

Your body has an internal clock (your circadian rhythm) that helps coordinate sleep, wakefulness, hormones, body temperature, metabolism and more. And one of the strongest things that keeps that clock on time is light. Morning light tells your body that the day has begun. As the day progresses and natural light changes, your body receives more cues about where you are in the day. When evening comes, darkness helps your body transition toward rest. The problem is that modern life can blur those signals.

We can spend the day indoors under relatively dim lighting, then spend our evenings surrounded by bright artificial light. We're getting less of the bright natural light our biology expects during the day and more artificial light at night.

That doesn't mean every light bulb or every screen is ruining your sleep. It means the overall pattern of light exposure matters.

What Should Be Happening at Night?

At night, your body is supposed to be moving toward a different physiological state. Melatonin rises. Your body temperature gradually drops. Your nervous system shifts toward rest, and your sleep architecture moves through its normal cycles throughout the night. This is when your body gets to work on all the things it can't prioritize in the same way while you're awake.

Deep sleep supports physical restoration, while REM sleep plays an important role in memory and emotional processing. When your circadian rhythm is well aligned, these processes happen in a more predictable rhythm. But when your light exposure is working against that rhythm, especially in the evening, it can make it harder for your body to recognize that nighttime has arrived. And that's where those frustrating nights can start:

You fall asleep but wake up later.

You feel tired but wired.

You wake up exhausted.

Or you simply can't seem to get into a deep, restorative sleep.

The Science Behind Light and Sleep

This isn't just an idea based on how our ancestors lived. There is a growing body of research looking at how evening light exposure affects melatonin, circadian timing and sleep.

Even ordinary room light can matter

Research has found that exposure to room light before bedtime can suppress melatonin and shorten the amount of time melatonin remains elevated during the night. And blue-enriched light can have an even stronger effect because certain wavelengths are particularly effective at signalling daytime to the brain.

You don't need a giant screen inches from your face for light to matter.

Your entire evening light environment counts.

Your bedtime matters too

Your circadian rhythm isn't just about whether you get eight hours of sleep.

Timing matters.

Research has found associations between very late sleep timing and poorer health outcomes. One large study of UK adults found the lowest cardiovascular disease risk among people whose sleep onset was between approximately 10 and 11 PM, while later sleep timing was associated with higher risk.

This doesn't mean you need to panic if you go to bed at 11:30 one night. It means that consistently living out of sync with your biological clock may matter more than we once thought.

Sleep happens in cycles

Sleep isn't one single state. Your brain moves through different stages of sleep throughout the night, including deep sleep and REM sleep. Deep sleep tends to be more concentrated earlier in the night, while REM becomes more prominent later.

That's one reason why when you sleep can matter, not just how many hours you get.

The Bigger Health Picture

Your circadian rhythm doesn't only influence sleep. It helps coordinate a huge number of processes throughout the body, including hormones, metabolism, body temperature, digestion and immune function.

When your daily light-dark rhythm is consistently disrupted, research has linked circadian disruption with changes in metabolic health, mood, cardiovascular health and immune function. This is particularly clear in research around shift work, where people are regularly exposed to light and activity at times when the body would normally be preparing for sleep.

So I don't think of light as just a “sleep hygiene” issue.

It's part of your overall environment.

The 24-Hour Light Strategy

The good news is that you don't need to completely overhaul your life. Think about light as something you can use throughout your entire day.

Morning: Get Outside

Try to get outside soon after waking. Natural outdoor light is dramatically brighter than typical indoor lighting, even on a cloudy day. Morning light helps anchor your circadian rhythm and gives your body a strong signal that the day has begun.

You don't need a complicated routine.

Go outside. Look toward the daylight (without sunglasses/glasses). Let your body experience the morning.

During the Day: Get More Natural Light

If you work indoors, make a point of getting outside during the day. Have your coffee outside. Take a walk. Eat lunch outdoors.

The goal is simply to give your eyes and body more exposure to natural daylight. The stronger your daytime light signal, the more wiggle room you have  with your evening.

Evening: Start Dimming Things Down

As the sun starts to go down, let your environment change with it. Dim the overhead lights. Use warmer, lower-level lighting like incandescent lights. Turn down the brightness on your screens.

And if you can, spend some time outside around sunset. You don't have to turn your evening into a wellness bootcamp.

Just start making your environment feel more like evening.

5 Things You Can Try Tonight

1. Turn off the overhead lights

After sunset, swap bright overhead lighting for smaller, warmer lamps. You don't need your entire house lit up like it's noon.

2. Create a little distance from your screens

If you can, reduce screen time in the hour or two before bed. If you need to use your phone or laptop, lower the brightness and consider using tools that reduce the amount of blue-enriched light reaching your eyes.

3. Get outside in the morning 

Even a short morning walk gives your body a much stronger light signal than sitting beside a window. Make it part of your morning routine.

4. Give your body some consistency

Try to keep your wake time and bedtime reasonably consistent. Your circadian rhythm likes predictable signals.

5. Use circadian glasses when you can't control your environment

This is the one I find especially interesting because, let's be honest, we don't always have control over our evenings.

Maybe you're working late. Maybe you're watching a movie. Maybe you're travelling. Maybe the lights in your home are still on because you have kids running around.You don't have to live in a cave. This is where circadian glasses can be another tool to consider.

I've been researching different options because there are a lot of products out there, and they aren't all designed in the same way. VivaRays is one I've been looking into, and I'm looking forward to trying my pair when they arrive in the mail this week! 

They also have some really cute styles, including glasses for kids. Back to School offer: August 23–30 –  kids' glasses are an extra 20% off.

For everything else, you can use my code MURIELLEZEKRY for 15% off.

This is an affiliate link, which means I may earn a commission if you purchase through my link, at no additional cost to you.

Your Body Isn't Broken

If your sleep has been off for years, it's easy to start thinking that your body is the problem.  Maybe you need another supplement. Another sleep tracker. Another protocol. Another thing to take before bed.

Sometimes the answer is much simpler.

Your body is constantly responding to its environment.

Light is one of the strongest environmental signals we have, and modern life has completely changed our exposure to it. We now have the ability to bring daytime into our homes long after the sun has gone down. That doesn't mean you need to eliminate every artificial light or become obsessed with darkness. It means you can start giving your body a little more of the contrast it naturally understands:

Bright days. Darker evenings.Consistent rhythms.

Start with one thing. Get outside in the morning. Dim the lights after sunset. Make your bedroom darker.

See what changes.

For me, changing my light environment has been one of the simplest shifts I've made for my sleep and it's made me look at my evenings completely differently.

The Bottom Line

We’ve made sleep so complicated. But one of the simplest places to start is light.

Get outside in the morning. Let your body see real daylight during the day. As the sun goes down, start dimming things around you and give your body the cue that the day is winding down.

You don't have to do everything perfectly. You don't have to give up your evenings. Just start paying attention to the light you're living in.

It’s one of those small environmental changes that can make a surprisingly big difference.

And if you want to take it a step further, you can check out the circadian glasses I’ve been looking into here.

Use code MURIELLEZEKRY for 15% off.

Affiliate disclosure: I may earn a commission if you purchase through my link, at no additional cost to you.