What is blue light?
Blue light is a tiny, visible part of the electromagnetic spectrum. As per the diagram below, the electromagnetic spectrum is made up of various rays and waves. A small part of this spectrum is made up of the light humans can see. This is called the visible spectrum. Of this visible spectrum, blue light is a small section, close to ultraviolet light.
Blue light has the shortest wavelengths of the visible light spectrum. This means that it produces a high amount of energy. Blue light, like ultraviolet light, can have a powerful effect on our bodies.
Blue light is not ‘bad’ or ‘dangerous’. It is completely natural. It is also used as a form of light therapy to treat people with circadian disorders or depression. However, historically, humans were only exposed to blue light during the day, when the sun is out. The sun is the only natural source of blue light.
In modern society, we are exposed to way higher levels of blue light, and more importantly, we are exposed to it in the evening and late at night. Much of our modern technology emits blue light, this includes, fluorescent lights, LED lights, computers, tablets, smartphones, TVs, etc. These things all have a higher concentration of blue light than the natural light we are used to. Plus, we are using all these devices after sundown.
How does blue light affect your sleep?
Humans have a natural sleep/ wake cycle known as the circadian rhythm. Light is the main cue that our bodies use to regulate our circadian rhythm. Blue light suppresses the body’s production of melatonin, the hormone which regulates sleep. This means that exposure to blue light after sunset can cause your body confusion and delay your circadian rhythm.
Because portable devices shine straight into your eyes and we often hold them quite close to our face, they are the most likely to cause a disrupted body clock. The human body clock is so sensitive to blue light that it has been shown to impact the circadian rhythm of people who are otherwise completely blind.
Read our full article on blue light and sleep here.
How does blue light effect you in other ways?
Although your circadian rhythm is mainly associated with sleep, recent research has shown that it actually plays a role in other regulatory functions in the body. Changes to our circadian rhythm can influence organ functions and impair thinking, as well as making it difficult to get to sleep. Some studies have linked circadian disruption to depression, obesity, diabetes and even cancer.
Additionally, blue light tends to flicker more than other colours due to its high energy wavelength. This flickering causes the eye strain you may have experienced when working at a computer all day. As well as hurting your eyes, the flicking is said to cause headaches and fatigue.
How do blue light blocking glasses work?
Blue light blocking glasses, as the name suggests, filter out the blue light that can disrupt your body clock. It’s best to wear them in the evening and night, or from sundown. You can use them if you are working late at the office or just at home watching TV. They are non-prescription, however, you can get them in a prescription version if you wear glasses. We recommended Baxter Blue’s Sleep collection.
The most effective blue light blocking glasses will have a tinted lens. But, if this isn’t for you, you could opt for some clear ones.
Blue light blocking glasses can also be helpful for people who travel a lot and want to minimise the effects of jetlag.
What else can you do to protect yourself from blue light?
The most effective and unpopular answer to this question is not to use technology at night. However, this isn’t always practical.
Most devices come with some sort of ‘night mode’ which will turn down the blue on your screen at night. This will give your screen a slight orange tinge which you get used to very quickly. But make sure you also turn down the brightness of the device. Having it as dim as possible will help with your blue light exposure. Additionally, make sure night lights and bathroom lights are low-wattage and warm.
Please note: This article is not to be used as medical advice. Please consult a medical professional before using any sleep treatments. This post may contain affiliate links.