Blue Light and Sleep: What is their relationship?

Kayla Newnam
Blue Light and Sleep: What is their relationship?

Blue light exposure has been a buzzword lately, but have you heard about the relationship of blue light and sleep? We'll share what blue light is and why it can affect sleep.

What is Blue Light?

There are different colors of light that are distinguished from each other based on how much energy they contain. These can also be described as different wavelengths of light. Sunlight contains all of the different colors of light, including blue light. Blue light is a wavelength of light that affects our levels of alertness and our sleep cycles. Electronic devices including televisions, computers, phones, and tablets all emit blue light.

A Brief History of Blue Light

For over two million years as humans evolved the only sources of light we were exposed to were sunlight/fire. We had no flat-screen televisions, smartphones, computers, tablets, or overhead LED lights. Then electricity and subsequently, artificial lighting was invented which enabled us to have access to bright light at night. This was an amazing human accomplishment. But there are always some potential downsides to any new technology.

This lighting eventually became more advanced and more ubiquitous leading to widespread light pollution throughout the world. Then smartphones were invented. Today, most of us have some level of addiction to our smartphones and feel naked without them. We stare at our phones all day long, until the very moment we go to sleep. We also watch large televisions that emit high amounts of blue light until late hours of the night. Let's admit it, we also work on our computers in bed. This isn't only an issue from the perspective of blue light but also the psychological consequences it carries with it. We never disconnect and relax.

What Is the Problem with Exposure to Blue Light? 

The blue light that is emitted from these devices tricks our brains into thinking that the sun is out, suppressing our sleep hormone melatonin. Melatonin is also known as the hormone of darkness because it is the darkness that prompts our brains to release melatonin to prepare us for sleep. Without darkness, we do not produce the same levels of melatonin, and our sleep quality suffers. 

Think about what our natural wake and sleep cycles looked like before the invention of artificial blue light. We woke up as the sun rose in the morning and were exposed to sunlight throughout the day until that sunlight gradually faded leading to sunset and darkness.

After the sunset, we created fires to provide warmth and light, but this was the only source of light we had. This red light produced by the fire was very calming and even though it allowed us to see, it did not inhibit our production of melatonin. We would sit around the fire until it was time for sleep where we would go to sleep for a refreshing slumber for the next 8-9 hours until we woke as the sun rose the next morning. Light became the most impactful signal to our biology in terms of its impact on circadian rhythms and sleep cycles. 

What Does This Mean?

We now have a mismatch between the environment in which our genes evolved and the environment we currently live in. This mismatch has caused massive disruption to our sleep length and quality. Our quality of sleep affects our health and happiness in so many different ways. Chronically poor sleep contributes to insulin resistance, poor glucose disposal, autoimmune disease, cognitive dysfunction, cancer, chronic fatigue, and virtually every other human disease known to man. Improving your quality of sleep will improve your energy, cognitive function, skin health, gut health, and mood. 

What if you are one of those people who watches TV and looks at your phone right before bed and still falls asleep and sleeps through the night? We all have different genetics and some people can get away with a lot more than others, but just because you can fall asleep does not mean the blue light exposure does not affect the quality of your sleep.

Think about how much better you would feel if you increased the amount of deep and rem sleep you experience. This would be an absolute game-changer for your health, mood, performance. Based on what we know about how sleep affects the immune system, you would almost certainly be in a better position to battle off viruses, which is more important now than ever. No matter what your sleep quality is like now, there is always room for improvement and optimization.

 

How To Minimize Blue Light Exposure at Night

Ideally, we would all live in nature and have no exposure to artificial light at all after sunset, but we live in a modern world, and living off the grid is not a realistic option for most of us. The next best option is to minimize our exposure to blue light at night. 

Use night mode

First, put your phone on night mode, which will limit your exposure to blue light by dimming the screen. An option that would be more effective than that is to not look at your phone at all at night. Keep your phone outside of your bedroom when you sleep. 

Try red bulbs

Install red light bulbs in the areas of the house where you turn the light on at night or get smart lights that can be adjusted to a red color, as it is shown to boost production of melatonin. If you cannot do this, then try not to use overhead lights at night. Overhead lights are particularly problematic, and it is a better choice to use lamps or flashlights. Use red light lights or candles at night to read or walk around.

Limit television at night

Limit how much you view television at night. Not only is the light coming from the television chock full of blue light but the type of show or movie you watch is often full of action, intrigue, or violence which will keep your mind on high alert and make it harder to relax before bed. If you do watch television you can change the settings to turn down the backlight, brightness, contrast, and sharpness. On some televisions, you can change the tint of color to look redder and therefore more favorable to sleep. Additionally, if you watch television try to watch a show or movie that is more calming and relaxing as opposed to something fast-paced and violent. 

Eliminate light from your bedroom

Another important consideration is to eliminate all light from your bedroom. Even a small green dot coming from an alarm or smoke detector can have a negative effect on your sleep. You would be surprised at how much these tiny amounts of light can negatively impact our sleep. Unplug these devices or get them out of your bedroom. If you cannot do that then cover the light with black duck tape or something else. One other note that is worth repeating is that if you can, don't sleep with your phone in your bedroom. You will feel better psychologically if the phone is out of the bedroom. If you use the phone as an alarm, then get another alarm. If you have to have your phone in your bedroom for another reason then put it in airplane mode and make the screen as red and as dark as possible. 

Try blue light blocking glasses

If you are unwilling or unable to do the things mentioned above and you simply must be exposed to lights and screens at night, then it is highly recommended to wear a pair of blue light-blocking glasses. These glasses filter out the blue light and will really help you get into sleep. Wear them for 1-2 hours before going to sleep. This can be a part of your nighttime routine. Perhaps after your shower or brush your teeth or do something else you do at night, then put the glasses on after and wear them until you go to sleep. Creating a consistent bedtime routine and making the glasses a part of your routine can make a significant difference in the quality of your sleep. 

The Bottom Line

Blue light exposure at night is so ubiquitous in our society today that most of us do not realize the impact it is having on our sleep. Blue light is not the only factor in sleep quality, but it is certainly a very important one. Simply putting on a pair of blue light blocking glasses a couple of hours before bed each night is one of the simplest and easiest ways to improve your sleep quality.