The Science Behind Better Sleep

Your lighting is working against you

Every night, millions of people struggle to fall asleep. They toss and turn, check their phones, and wake up feeling exhausted. Most blame stress, caffeine, or poor sleep habits, but there's a contributing factor that's rarely discussed: your lighting.

The truth is, modern LED bulbs are designed for visibility, not to support your body's natural rhythms. They emit high levels of blue-enriched light that can affect your body's natural sleep-wake cycle, even hours before bedtime. For many people, poorly timed lighting may be working against their sleep without them realizing it.

What is blue light?

All light is made up of different colours, each with its own wavelength. The visible light spectrum ranges from about 380 nanometers (violet) to 700 nanometers (red).

Blue light is the part of the spectrum between 400-500 nanometers. It has a short wavelength and high energy. You get it from the sun, your phone, your computer, and your light bulbs.

When we talk about light being "warm" or "cool," we measure it in Kelvin (K):

• Low numbers (2000-3000K) = Warm light that looks orange or yellow (like a candle or sunset)
• High numbers (5500-6500K) = Cool light that looks bright white or slightly blue (like midday sun)

Here's the key relationship: Higher colour temperature means more blue wavelengths.

A 6500K bulb contains much more light in that 400-500nm blue range than a 2700K bulb. So when we say "avoid blue light at night," we mean use low colour temperature lighting (2700-3000K), which naturally contains fewer blue wavelengths.

What happens in nature:

• Sunrise/Sunset: 2000-3000K (warm, minimal blue)
• Midday sun: 5500-6500K (bright white, rich in blue)

Your body evolved to read these signals.

• High blue-light content = daytime, be alert
• Low blue-light content = nighttime, start winding down

The problem

Your body has an internal 24-hour clock called your circadian rhythm. This biological clock is controlled by the suprachiasmatic nuclei in your brain and synchronizes your sleep, hormones, body temperature, and energy levels with the natural day-night cycle.

Light is the strongest signal that tells this clock what time it is. When light enters your eyes, special cells in your retina send signals directly to this master clock in your brain, telling it whether to be alert or prepare for sleep.

Here's where standard lighting fails you:

Walk into any store and you'll see bulbs labeled "soft white" (2700K), "bright white" (4000K), or "daylight" (5000K). You pick one and screw it in. That bulb will emit the exact same colour temperature 24 hours a day.

A 2700K "warm white" bulb? That's fine for evening, but it's too dim and warm for waking up energized in the morning.

A 5000K "daylight" bulb? Great for morning alertness, but devastating for your sleep when you use it at night.

Most people choose something in the middle, around 3000-4000K. Its a compromise. But compromises don't work with biology. Your body doesn't want "okay lighting all day." It needs high colour temperature in the morning (rich in blue wavelengths to suppress melatonin and boost alertness) and low colour temperature at night (minimal blue wavelengths to allow melatonin production).

The real problem: Standard bulbs are static. Your biology is dynamic.

When you use a fixed bulb at 4000K in the evening, it's still sending blue-rich light into your eyes hours before bed. Exposure to blue-rich light before bed disrupts melatonin production and delays your natural sleep timing, making it harder to fall asleep when you want to.

This can contribute to feeling "wired but tired" - your body is exhausted, but your brain may still be receiving signals that it's daytime.

We often compound this by using phones, computers, and TVs (all 5000K+) in the evening, adding even more blue-enriched light exposure before bed.

The result? For many people, poorly timed lighting may be one of several factors affecting their sleep quality. While lighting isn't the only factor - stress, caffeine, sleep disorders, and other health conditions all play important roles, it's one that's often overlooked and relatively straightforward to address.

The solution

Your ancestors didn't have this problem. They woke to the energizing light of sunrise (5500-6500K) and wound down to the warm glow of fire (2000-3000K). Their circadian rhythms stayed synchronized with nature because the light in their environment changed throughout the day.

An approach that may help: making your lighting adaptable to support your body's natural rhythms.

Our circadian LED bulbs are adjustable from 2700K to 6500K, allowing you to match your lighting to your body's natural rhythm.

How it works:

Inside each bulb are red, green, and blue LED elements. By adjusting the balance between them through the app, you can shift the bulb's colour temperature:

• Morning (6AM-10AM): 5500-6500K High blue wavelength content can help suppress melatonin naturally and signal "wake time" to your brain, potentially supporting morning alertness and energy
• Midday (10AM-6PM): 4000-5000K Neutral, bright light may help maintain energy and focus throughout your productive hours
• Evening (6PM-10PM): 2700-3000K Warm light with minimal blue wavelengths allows melatonin production to begin naturally, helping your body recognize that sleep is approaching

You control these settings through the app, adjusting the colour temperature to match different times of day and your personal schedule. Set your bedroom to 6500K in the morning for an energizing wake-up, then switch it to 2700K in the evening as you wind down.

This isn't a gimmick - it's working with your biology instead of against it.

Standard "smart bulbs" let you change colours for ambiance or parties. That's entertainment. This is different. These colour temperatures are scientifically calibrated to match your body's biological needs throughout the day.

By the time you go to bed, you've spent hours in warm, low-blue light designed to support natural melatonin production. This approach aims to help your body prepare for sleep more effectively. While individual results vary and lighting is just one factor in sleep quality, many people find that properly timed light exposure helps reduce the time it takes to fall asleep.

The research

This isn't pseudoscience or wellness trends, it's backed by decades of research from leading institutions. If you're interested in further optimizing your sleep, Andrew Huberman, a Stanford neuroscientist and popular wellness educator, had Dr. Matthew Walker, a world-renowned sleep scientist, on for a 6-part podcast series where they discussed sleep. In Episode 2 ("Protocols to Improve Your Sleep"), they specifically discuss how lighting affects the body's mechanisms to fall asleep and wake up.

Expert Perspective on Light and Sleep

In a conversation with Dr. Andrew Huberman, sleep researcher Dr. Matthew Walker discusses how light exposure affects circadian rhythms and sleep. Walker explains that bright light exposure in the evening can disrupt natural melatonin production, while bright, cool light in the morning and warmer lighting before bed may support natural sleep-wake patterns.

Note: Dr. Walker's comments are general scientific observations about light timing and circadian biology. He does not specifically discuss, test, or endorse any particular lighting products, including SolsticeGlow.

Listen to the episode

Key Scientific Studies:

Blue Light Suppresses Melatonin

Harvard researchers found that blue light (460nm) suppressed melatonin significantly more than other wavelengths and was particularly disruptive to circadian timing when encountered in the evening.

Source: Lockley et al., Journal of Clinical Endocrinology & Metabolism (2003)

Read the study

Evening Screen Use Disrupts Sleep

A landmark Harvard/PNAS study showed that evening use of light-emitting devices prolonged time to fall asleep, delayed the circadian clock, suppressed melatonin, reduced REM sleep, and decreased next-morning alertness.

Source: Chang et al., Proceedings of the National Academy of Sciences (2015)

Read the study

Dynamic Lighting Improves Sleep Quality

A 2025 study found that dynamic lighting (bright/cool during day, dim/warm at night) improved sleep quality by 43%, increased total sleep time by over 3 hours, and improved sleep efficiency by 16%.

Source: Obeidat et al., Scientific Reports (2025)

Read the study

Important Disclaimer

SolsticeGlow bulbs are designed to provide adjustable colour temperature lighting that can be timed throughout the day. While peer-reviewed research demonstrates that light timing affects circadian rhythms and sleep-wake cycles, individual results may vary based on numerous factors including overall health, sleep habits, environment, and lifestyle.

These products are not medical devices and are not intended to diagnose, treat, cure, or prevent any disease or medical condition. If you have persistent sleep difficulties, insomnia, or other sleep disorders, please consult with a qualified healthcare professional.

The scientific studies referenced on this page were conducted independently and do not specifically test or evaluate SolsticeGlow products. References to these studies are provided for educational purposes to explain the science of circadian lighting