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Artificial light is all around us - whether it’s a lamp in your room or overhead lights at work, they illuminate our environment so we are not living in darkness.

Not only that, but we are spending more time than ever before in front of screens like computers, mobile phones, and tablets. 

These artificial light sources have been so engrained with our way of life that we tend to overlook the effects that these light sources have on our human biology.  

Studies have found that exposure to light has a direct relationship with how our bodies regulate between the sleep-wake cycles - especially blue light. 

Blue light can cause major implications to your sleeping pattern and maybe the reason why you’re having trouble falling asleep or staying asleep at night. 

That doesn't mean that we should avoid artificial light sources because the benefits of artificial light are undeniable. There’s no way we would be able to function without it in the world we live in today.

However, it is important to understand that there are consequences from the constant bombardment of blue UV light emitted by these artificial light sources.

Let's get into it. 

What is Blue Light

Light is comprised of a spectrum of light rays ranging from red, orange, yellow, green and blue. Light rays are not created equal and each has specific characteristics. 

Light rays on the red side of the visible light spectrum have longer wavelengths and less energy, while light rays on the blue side have short wavelengths and more energy. 

The relationship between Light and Sleep

A 1981 study conducted by Dr. Charles Czeisler of Harvard Medical School found that daylight regulates your circadian rhythm with the environment around you. 

Circadian Rhythm

A circadian rhythm is approximately a 24-hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria. It is often referred to as the “biological clock” and determines our sleeping and eating patterns. 

Each individual’s circadian rhythm will vary - people that tend to stay up late (night owls) will have a slightly longer circadian rhythm and those who are prone to waking up early (early birds) will have a shorter circadian rhythm. 

Effects of Blue Light 

Blue light is not all bad. In fact, light and blue wavelengths are actually beneficial for you. Blue light elevates your mood, increases your reaction time, and makes you more attentive and alert. 

Perfect for daytime tasks and activities. 

The problems occur in the evening when we need to rest and sleep. The prevalence of artificial lighting and screens, especially after sundown, disrupts our ability to fall asleep. 

Exposure to light has been known to suppress melatonin secretion. Melatonin is a hormone that greatly influences your circadian rhythm by regulating your sleep cycle.

Your body begins to produce melatonin in the evening, when it’s dark, signalling your body that its time for sleep.  In the morning, daylight has the opposite effect and signals your body to produce less melatonin to prepare for your daily activities. 

Daylight is not the only form of light that has an effect on your body’s ability to produce melatonin. In general, all light will suppress melatonin secretion.

However, blue light is the most powerful wavelength in the visible light spectrum and affects melatonin secretion at a much greater scale.

Our bodies have used light as a way to calibrate itself to the environment we live in. Unfortunately, our systems have been compromised with the rise of modern technology.

The advent of artificial lighting, screens from daily gadgets (TVs, computers, mobile phones etc.) and energy-efficient lighting create a conflict with how our bodies regulate our sleep-wake cycles. 

LEDs or light-emitting diodes have become increasingly popular because they are far more energy-efficient than fluorescent bulbs. 

They can be found in both lighting systems and screens for your devices. Although LEDs require less energy to produce light they are a culprit for producing more blue light. 

Blue Light Case Study

A Harvard study was conducted outlining how different types of light affect melatonin secretion. In the experiment, researchers from Harvard exposed the subjects to blue and green light independently for 6.5 hours with equal brightness of each colour. 

What did the researchers find?

They concluded that blue light suppressed melatonin secretion and shifted circadian rhythms by double the amount compared to exposure from green light (3 hours vs 1.5 hours).

Another study was done by researchers at the University of Toronto looking into the effects of blue light on an individual’s melatonin levels. 

In the study, the researchers from the University of Toronto analyzed the differences in melatonin levels for people that work in bright indoor lighting environments who wear ‘blue-light-blocking’ goggles and people that did not wear ‘blue-light-blocking’ goggles in dim light.

What were the results of the study?

The researchers at the University of Toronto found that the melatonin levels between the two groups studied were relatively similar to each other.

So, what does this mean?

The evidence points to a strong relationship between the suppression of melatonin secretion caused by blue light. 

Exposure to light with high amounts of blue wavelengths are conducive to working under bright environments with indoor lighting.

The results found that wearing blue-light-blocking goggles reduces the adverse effects of blue light on melatonin secretion to similar levels as being in an environment with dim lighting. 

This further supports the hypothesis that blue light has a direct influence on the production of melatonin.

This means that overexposure to blue light can disrupt your circadian rhythm which can result in a lack of sleep or poor sleep quality.  

How To Reduce Blue Light Exposure For a Better Sleep

The fact is, we can’t avoid blue light. Unless you’re willing to live ‘off-grid’ away from city lights and technology there’s no way of escaping overexposure to blue light.

Thankfully there are steps you can take to mitigate your exposure to blue light, increase your melatonin levels and potentially fix any problems with your sleeping patterns. 

6 Tips For A Better Sleep

1.) If you work night shifts, or just tend to stay up late using electronic devices, it would be beneficial to invest in a pair of ‘blue-light-blocking’ glasses/goggles. 

2.) Install apps that filter blue/green wavelengths.

3.) Purchase specialty LED bulbs that emit specific light geared for day and night. 

4.) Avoid screen time two to three hours before sleeping

5.) Use red dim lights as a night light. Red light has the least effect on your circadian rhythm.

6.) Get plenty of light in the daytime. Light exposure during the day boosts alertness, elevates your mood, helps to regulate your circadian rhythm and improves your ability to fall asleep at night.

*The content on this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions or contact us at 403-764-6161 to speak to one of our doctors of optometry.