By now, we all know that sleep is one of the most important factors of healthy living. In our busy lives, it’s easy to sacrifice a few hours of sleep in order to accomplish everything on our to-do list, not to mention rewarding ourselves with a little screen time at the end of the day. In the modern world, not only do we sleep much less, but our sleep quality has declined, which has been linked to depression, obesity, type 2 diabetes, some types of cancer, and even heart disease.
One of the most recognized culprits for our poor sleeping habits is the use of artificial, bright lights, especially when it comes to the blue wavelength-emitting digital devices we tend to rely on even when we are safely tucked in bed.
Our laptops, tablets, and smartphones (even our old flip cell phones) all emit blue wavelength light, which although environmentally friendly, can disrupt our circadian rhythm, messing with our melatonin levels and sending our brain false signals that it’s still daytime and not yet time for that good night's sleep we're chasing so hard after.
What is Blue Light?
Sunlight is a type of electromagnetic radiation made of yellow, violet, red, orange, blue, green, and indigo lights. Each light has its own energy and wavelength, and put together we see them as white light. The human eye can register wavelengths between 380 and 740 nanometers (nm) and those waves form the visible electromagnetic spectrum.
Blue light rays have the shortest wavelengths (from 400 to 490 nanometers), but the highest energy. These short wavelengths enter the eye unfiltered and reach deep, all the way to the retina.
Until artificial light sources became commonplace, the sun was the major source of lighting, and people spent their evenings in darkness broken only by a candle or a gas lamp. These days our evenings are illuminated, and we take the convenience of light for granted.
Besides its natural form as sunlight, blue light is present in many indoor artificial sources:
- Fluorescent light bulbs
- LED light bulbs
- Computer monitors
- Tablet screens
- Smartphone screens
- Gaming systems
The light from our digital devices mostly appears white, but there are a lot of HEV (high energy visible lights) blue lights that reach us, even when we turn on night shift mode. We receive more blue light from the sun than from artificial sources, yet our eyes are not designed for these prolonged hours of blue light exposure, which can lead to many adverse effects.
Is Blue Light Harmful?
In recent years, researchers and the medical community have been working hard on trying to understand the harmful effects of blue light on our health as we are getting more and more addicted to our electronic gadgets.
Here are some of the possible results of spending long hours in front of our screens:
- Digital eye strain or computer vision syndrome is a serious medical issue which affects work productivity and learning and is linked to extended use of digital devices. The symptoms we might experience are blurry vision, dry and irritated eyes, headaches, difficulty concentrating, and neck and back pain.
- Macular degeneration can be a result of prolonged exposure to blue light which, unfiltered, reaches deep into the eye all the way to the retina, causing damage to light-detecting cells, according to a study by The University of Toledo.
- Age related macular degeneration is a leading cause of blindness.
- Researchers have linked not getting enough sleep to Depression and other mental illnesses, and one of the main reasons we are not getting a healthy amount of sleep is having a light on at night.
- A study done at Harvard has suggested that Type 2 diabetes and obesity could be triggered by nighttime working as continuous exposure to blue light might change our system’s metabolic processes and prevent the ability to process sugar.
- Heart disease
How Does Blue Light Affect Sleep?
Our internal clocks are naturally connected to the environment. We are supposed to be productive and active during the daylight hours, and go to sleep at night, following our internal biological clock.
Blue light rays are beneficial during daylight hours because they boost attention, reaction times, productivity, and mood, but too much light at night can keep us awake when we should start winding down to sleep.
After sunset, light throws out of whack the circadian rhythms. These physical, mental, and behavioral changes that follow a roughly 24-hour cycle regulate our sleep-wake routine. More than any other kind of light, exposure to blue light suppresses the production of a hormone called melatonin and can create sleep problems when exposed before going to bed. The brain is tricked into thinking it’s still daytime, so instead of getting tired and sleepy, we are still alert and our thoughts are racing a hundred miles per hour.
Most Americans spend an average of 7 hours a day in front of their screens, which is definitely a huge chunk of time spent on staring at blue light. To make it worse, most of us admit that we don’t leave our beloved electronic devices behind once the work day is over, but reach out for them while we are in bed. That could be an invitation for insomnia.
What Are Blue Light Filters and How Do They Work?
Blue light filters are specifically designed to eliminate most of the HEV blue light rays from the spectrum. We don’t need to eliminate blue light completely, as it is mostly beneficial to us, so most blue light filters are designed to filter a certain percentage of blue light from the visible light spectrum. The most important role of blue light filters is to block the most harmful frequencies between 400 and 440 nanometers, which can alleviate many symptoms connected to the extended use of the digital devices. That way, some of the beneficial blue light can come through freely to keep us in sync with our circadian rhythms, while allowing our eyes to rest.
There are some specially made filters which are designed for nighttime use and they block blue light in frequencies up to 480 nanometers.
Nowadays, you can buy a blue light filter screen for your computer or tablet, and most newer smartphones are equipped with some form of blue light protection.
How Can Blue Light Filters Help You Sleep Better?
Blue light filters in products such as blue light glasses are not worn during sleep to block blue light, but rather as a tool before sleep to help your body’s internal mechanisms prepare for a full night’s rest. When the sun goes down, wearing blue light filtering glasses can help block the blue light emitted from our phones and other electronics we love to enjoy at the end of the day so that our brains and bodies can prepare for bed. Filtering blue light in the evening helps us get better sleep because, with the artificial blue light being blocked and the sun nowhere in sight to tell our brains to stay awake, our brains can release the right hormones to tell our bodies it’s time to wind down for the day. By bedtime, we feel more relaxed and ready to go to sleep thanks to the increased level of sleep hormones that weren’t inhibited by blue light. Additionally, those sleep hormones play a role in helping us to sleep more soundly through the night, too, making for much-needed quality rest.
There are several benefits of using blue light filters throughout the day, but their help in restoring our internal sleep-wake cycle is especially instrumental.
- Blue light filters help increase melatonin production. It seems we cannot avoid using our digital devices at night which causes unnatural alertness and inability to sleep. Without proper rest, we feel tired, drowsy, and sluggish in the morning, and our productivity and focus suffer greatly. Blue light filters eliminate most of the harmful light frequencies that disrupt the circadian rhythm. When we use them at night, melatonin production is resumed and the biological clock is working like it’s supposed to do, leaving us rested and ready for the busy morning. Studies show that when we wear blue light blocking glasses at night while sitting in a room filled with artificial light staring at our computer screen, the production of melatonin is uninterrupted, as if we were in complete darkness.
- They help increase orange light. Blue light filters reduce the amount of blue light in digital devices, which results in an increased amount of orange light. While blue light is proven to suppress the secretion of sleep-inducing melatonin, orange light stimulates drowsiness. Researchers are still not certain why this happens, speculating that the reasons might date back to the days before artificial light was introduced to mankind. Sunset marked the end of the working day, which prompted the body to slow down, relax, and get ready for sleep. Blue light exposure from our electronic devices at night hampers this effect, but the impact of orange light can be significantly increased by using a blue light filter.
- Blue light filters help us sleep better which reduces mental health problems. When blue light emission is decreased and melatonin production increased, our internal biological clock resets and our natural processes continue smoothly. This in turn helps metabolic processes, the immune system, our mood, and cognitive functions, impacting positively on our overall health. A study published in Chronobiology International revealed great improvements in insomnia and mood in almost half of bipolar patients who used blue-blocking glasses.
- Blue light filters help shift workers. Maintaining a regular sleep schedule is essential for our wellbeing, but for many of us who are forced to work different shifts, getting into a healthy sleeping routine could be a problem. Shift workers are at a high risk of health problems caused by a lack of sleep and using blue light blocking glasses an hour or two before bedtime can help them with the regulation of their sleep-wake process.
Wrapping It Up
Blue light exposure from our digital gadgets has been linked to disrupted sleep patterns and insomnia. Sure, the best advice is to limit the time we spend in front of the screen at night, playing a video game, or scrolling on Facebook, but we all know that’s not going to happen any time soon.
Now that we have blue light filters, and blue light blocking glasses in particular, we don’t have to go to such drastic measures. We can keep using our smart devices even at bedtime knowing that our natural biological clock will continue to work perfectly.