How Light Affects Sleep: Why Darkness Matters for Melatonin Production

Every summer, I find myself having the same conversation with customers.

Some live in Sweden, where the evening sky stays bright until nearly midnight. Others are in Norway, Finland, Canada, or northern Scotland, where summer mornings begin long before they are ready to wake up.

The question is always similar:

“Why am I so tired, yet I can’t fall asleep?”

For a long time, I thought the answer was stress, caffeine, or simply getting older. While those factors certainly matter, I eventually learned that one of the biggest influences on our sleep is something we rarely think about.

Light.

Not just the light from our phones or computers, but every source of light that reaches our eyes after sunset.

Understanding how light affects sleep completely changed the way I think about bedtime. It also changed how I designed our silk sleep mask—not simply as an accessory, but as a tool that helps create one of the most important conditions for healthy sleep: darkness.

Your Body Doesn’t Follow the Clock—It Follows Light

Most people assume we sleep because we’re tired.

In reality, our bodies rely on something much more sophisticated: our circadian rhythm.

Often called the body’s internal clock, the circadian rhythm regulates hundreds of biological processes throughout the day, including:

• Sleep and wake cycles
• Hormone production
• Body temperature
• Digestion
• Mental alertness
• Immune function

The strongest signal controlling this internal clock isn’t time.

It’s light.

Special cells in the retina detect environmental light and send signals directly to a small region of the brain called the suprachiasmatic nucleus (SCN), often referred to as the body’s master clock.

When your brain senses bright light in the morning, it tells your body:

“It’s daytime. Stay awake.”

As daylight fades, those signals weaken.

Your brain begins producing melatonin, the hormone that prepares your body for sleep.

This natural transition has guided human sleep for thousands of years.

What Is Melatonin?

Melatonin is often called the “sleep hormone,” but that description isn’t entirely accurate.

Melatonin doesn’t force you to sleep.

Instead, it tells your body that night has arrived.

As melatonin levels rise, your body begins preparing for rest.

You may notice yourself:

• Feeling calmer
• Becoming less alert
• Yawning more frequently
• Feeling sleepy

In healthy adults, melatonin production usually begins around two to three hours before bedtime, provided the environment becomes dark enough.

This is where modern life creates a problem.

How Light Suppresses Melatonin Production

Our ancestors experienced bright days and dark nights.

Today, many of us experience bright days and bright nights.

Streetlights shine through bedroom windows.

Televisions stay on until bedtime.

Phones, tablets, laptops, and LED lighting extend daylight well into the evening.

Even relatively low levels of light reaching the eyes can delay melatonin production.

Blue wavelengths of light, commonly emitted by LED screens and cool-white lighting, are particularly effective at signaling “daytime” to the brain.

As a result, your body delays the biological processes that normally help you fall asleep.

Many people describe the experience like this:

“I’m exhausted, but my brain won’t switch off.”

Often, that’s exactly what’s happening.

Your body is physically tired.

Your brain simply hasn’t received the signal that night has begun.

Why Darkness Is Essential for Better Sleep

Darkness isn’t just the absence of light.

It’s an important biological cue.

When your sleeping environment becomes darker, your brain can maintain normal melatonin production and support a more stable circadian rhythm.

Many sleep specialists recommend creating the darkest bedroom possible by:

• Using blackout curtains
• Turning off electronic devices
• Covering LED indicator lights
• Avoiding screens before bed
• Wearing a comfortable sleep mask when needed

These small changes help reduce unnecessary light exposure during the hours when your body naturally prepares for sleep.

Summer Makes Sleeping More Difficult Than Many People Realize

Living in Sweden has given me a new appreciation for how powerful natural light really is.

Summer evenings are beautiful.

The golden light lasts for hours.

Sunsets happen incredibly late.

Morning sunlight returns long before many people intend to wake.

It’s one of my favorite parts of living here.

It’s also one of the biggest challenges for good sleep.

Even with curtains closed, early morning daylight often leaks into the bedroom.

Your brain doesn’t necessarily know it’s only 4:30 a.m.

It simply detects light.

For shift workers, frequent travelers, new parents, and anyone who sleeps during the day, the challenge is even greater.

Their bodies constantly receive mixed signals about when it’s time to rest.

Why I Started Sleeping With an Eye Mask

Years ago, I bought my first sleep mask while travelling.

It worked well enough on airplanes, but I never considered wearing one at home.

Eventually I gave it another try during one particularly bright Swedish summer.

The difference surprised me.

Not because the mask magically made me fall asleep.

Instead, it created something my bedroom couldn’t always provide.

Darkness.

That simple change made it easier to relax, especially during bright mornings.

Since then, sleeping with an eye mask has become part of my nightly routine.

Not All Sleep Masks Feel the Same

Over the years I’ve tried masks made from cotton, memory foam, polyester, satin, and silk.

Many blocked light reasonably well.

Some felt heavy.

Others became hot after an hour.

A few pressed uncomfortably against my eyes.

Eventually I realized that comfort matters just as much as darkness.

If something irritates your skin or makes you feel warm, you’re less likely to wear it every night.

That’s one reason I kept returning to natural silk.

Why We Chose 30 Momme Mulberry Silk

When we began designing our own sleep mask, we wanted to create something that felt luxurious without sacrificing practicality.

We chose 100% Grade 6A Mulberry silk in a substantial 30 momme weight.

Most silk sleep masks use lighter silk.

There’s nothing inherently wrong with that.

However, higher momme silk offers several advantages.

Its weave is denser, making it more durable for everyday use.

It maintains its smooth finish beautifully over time.

It feels rich without feeling stiff.

And because silk is naturally breathable, it remains comfortable throughout the night.

We also chose 100% silk filling instead of synthetic alternatives because we wanted every layer touching the skin to reflect the same premium quality.

These decisions weren’t made for marketing.

They were made because we wanted to create something we’d genuinely enjoy using ourselves for years.

Can a Silk Sleep Mask Improve Sleep?

A sleep mask isn’t a cure for insomnia.

Nor can it replace healthy sleep habits.

Good sleep still depends on many factors, including stress management, consistent bedtimes, exercise, and limiting caffeine late in the day.

However, reducing unnecessary light exposure removes one obstacle that may interfere with your body’s natural sleep signals.

Many people find that wearing a comfortable sleep mask helps them:

• Fall asleep more easily
• Stay asleep longer
• Wake less often during bright mornings
• Rest more comfortably while travelling
• Nap during the day
• Adapt to changing time zones

The key isn’t the mask itself.

The key is the darkness it helps create.

Small Changes Often Make the Biggest Difference

People often search for complicated ways to improve sleep.

Supplements.

Expensive gadgets.

New mattresses.

While those may help in certain situations, some of the most effective habits are surprisingly simple.

Dim the lights during the evening.

Put your phone away before bed.

Keep your bedroom cool and quiet.

Reduce unnecessary light exposure.

Protect your body’s natural melatonin production.

These habits work with your biology instead of against it.

Better Sleep Begins With Better Darkness

I’ve come to believe that luxury isn’t about owning more things.

It’s about improving the everyday experiences that matter most.

Sleep is one of them.

We spend roughly one-third of our lives sleeping.

The environment we create each night influences how we feel every morning.

If a simple habit—like creating a darker sleeping environment—helps your body follow its natural rhythm, then it’s one of the easiest investments you can make in your wellbeing.

Our silk sleep mask was created with that idea in mind.

Not to promise perfect sleep.

But to help remove one of the most common obstacles standing in its way.

Because sometimes, the most powerful sleep aid isn’t another product.

It’s simply giving your body the darkness it has always expected.

Frequently Asked Questions

Does light affect sleep?

Yes. Light is one of the most important signals that regulates your body’s internal clock, known as the circadian rhythm. Exposure to bright light in the evening can delay your body’s natural preparation for sleep by suppressing melatonin production, making it more difficult to fall asleep.

Does darkness increase melatonin?

Darkness doesn’t directly create melatonin, but it signals your brain to begin producing it. As light levels decrease in the evening, the brain naturally releases melatonin, helping prepare your body for sleep.

Can sleeping with an eye mask improve sleep quality?

Many people find that wearing a sleep mask helps create a darker sleeping environment, especially if their bedroom is affected by early morning sunlight, streetlights, or other sources of light. Reducing light exposure may help support a more restful night’s sleep.

Is a silk sleep mask better than a cotton sleep mask?

Silk is naturally smooth, breathable, and gentle on delicate skin. Many people prefer Mulberry silk because it helps reduce friction around the eye area while remaining comfortable throughout the night. The best choice ultimately depends on personal preference, but silk is often valued for its softness and temperature-regulating properties.

Why does summer daylight make it harder to sleep?

In regions with long summer days, such as Sweden and other Nordic countries, daylight can extend late into the evening and return very early in the morning. Because light helps regulate your circadian rhythm, prolonged daylight may make it more difficult for some people to fall asleep or stay asleep.

Can a sleep mask increase melatonin?

A sleep mask doesn’t produce melatonin or directly increase its levels. However, by helping block unwanted light, it can support the dark environment your body naturally associates with nighttime, which may help maintain normal melatonin production.

What is the circadian rhythm?

The circadian rhythm is your body’s internal 24-hour clock. It regulates sleep, wakefulness, hormone release, body temperature, and many other biological functions. Light is the primary environmental cue that keeps this internal clock aligned with the day-night cycle.

How can I reduce light exposure before bed?

Simple habits can make a difference, including dimming household lights in the evening, limiting screen time before bed, using blackout curtains if needed, and creating a darker sleep environment. If outside light is difficult to control, a comfortable sleep mask can also help reduce light reaching your eyes.

Why choose a 30 momme Mulberry silk sleep mask?

A 30 momme Mulberry silk sleep mask uses a denser, more durable silk weave than lighter-weight silk. It offers exceptional softness, long-lasting quality, and a luxurious feel while maintaining the natural breathability and smoothness that make silk comfortable for nightly use.