In recent years, blue light has become a health and welfare concern for many as we increasingly find ourselves exposed to more and more of it in our daily lives.
One of the main worries is that overexposure to blue light is having a negative impact on the quantity and quality of our sleep. But, is there any science behind these concerns?
Blue light is a form of light that falls within our visible spectrum – the light that we can see. Blue light is present naturally in sunlight, but many devices and screens also emit this light. As a low wavelength form of light, it has a particularly high energy output. Blue light can be broken into two subsections – nonharmful and potentially damaging.
Blue light covers the light wavelength between 400nm and 495nm - from 450nm and below, this light becomes potentially harmful as it begins to approach the ultraviolet range. Overexposure to ultraviolet light, or UV, is well known for its links to skin cancer and other health conditions. Playing an important role in our evolution, blue light is a key part of our environment that informs and regulates our circadian rhythm for sleep.
Put simply, the circadian rhythm is constructed of changes that occur over the course of a daily cycle – these can be mental and physical. Our circadian rhythm is influenced by factors such as temperature, medication, hunger and, importantly in this case, light.
Our circadian rhythm is why we tend to feel tired, hungry or energised at different points during the day – they are controlled and created by our biological clock. Circadian rhythm can cause the release of different chemicals and hormones in our bodies.
Importantly in the context that we’re talking about, our circadian rhythm affects the release of melatonin into our bodies Melatonin is the hormone that regulates the process through which we fall asleep and wake up, causing us to become sleepy when awake and the reverse when asleep.
As an example, to tie this all together, when the sun goes down our circadian rhythm picks up that there has been a decrease in blue light and causes the release of melatonin, which in turn makes us sleepy.
Similarly, through different triggers, we tend to get hungry at around the same time every day and our body temperatures go up and down as the day goes on. Our bodies are triggered into behaving in a certain way because of our circadian rhythm.
As mentioned before, the biggest producer of natural blue light is the sun. The presence of blue light is thought to be one of the factors that influence our circadian rhythm and sleep, as our bodies associate it with daylight and an expectation of hours of activity.
Artificial blue light is not distinguished by the body and is treated the same way as natural sources. While this may not have much of an impact on our circadian rhythm during the day, it becomes a serious problem when the sun goes down and our bodies should be preparing for sleep.
When we use blue light-emitting devices before sleeping, they can trick our circadian rhythm into thinking that it is still daylight, making it harder for us to power down and fall asleep.
Getting enough high-quality sleep is incredibly important to our bodies, beyond simply affecting how tired or awake we feel. Our sleeping behaviours in this regard are often known as our sleep hygiene. Poor sleep hygiene can include:
• waking up regularly for activities in the night
• sleeping at irregular hours
• drinking alcohol or caffeine before bed
• sleeping on an uncomfortable bed
• using devices directly before going to bed
Bad sleep hygiene can have serious consequences for the quality of your sleep, which in turn can have deeply negative effects on your health. Poor sleep has been directly linked to:
• Weight control issues
• Heart problems
• A poor immune system
• Decreased fertility
• Poor mental health
It’s safe to say that the occasional late-night won’t have too big of an impact on your health, but a regular pattern of poor sleep will have long term consequences that you should be aware of.
The general standing advice with regards to blue light at night is that you cut out all device usage an hour before going to bed. While this might be possible for some people, it is certainly difficult to follow for others – especially those whose existing sleep routine involves watching TV in bed or like to catch up on the day's social media before getting some shut-eye.
On top of that, devices with screens aren’t the only artificial sources of blue light that we encounter at night - LED bulbs and fluorescent lights also emit this light. There is a general trend towards using LED bulbs as they are more energy-efficient and better for the environment, but this means that we are all being exposed to more blue light at night-time.
So, unless you plan to turn all the lights off and sit in darkness for an hour before bed, there is no real way to completely cut out blue light before heading to bed.
With no real way to cut down your exposure to blue light, whether you want to change your night-time behaviour or not, what can you do to reduce the impact that blue light is having on your sleep? Kanturo blue light filtering glasses for men and women use our unique lens technology to stop unwanted blue light from reaching your eyes.
By wearing a pair of our glasses throughout the day and in the evening, you will reduce your exposure to blue light from screens and other sources, stopping the impact that this might be having on your sleep. With our glasses, you can continue you to scroll away without having to worry about how the blue light is affecting your sleep hygiene.