Have you ever seen a rainbow? A myriad of colours sitting aloft in the sky, shining and shimmering and splendid. Rainbows are formed when the sunlight refracts and reflects against water droplets, which results in the visible spectrum of colours that your eyes are able to see. This spectrum is made up of seven different types of light — red, orange, yellow, green, blue, indigo, and violet.
In particular, blue light is one of the most common ones we see every day. Sunlight is the foremost source of blue light during the day — we see it every day in the blue sky. At night, natural blue light is more scarce, but man-made emitters of blue light include fluorescent lights and LED screens. This means most of your electronic devices — smartphones, tablets, computers, televisions — all of these are blue light emitters.
Blue light has been talked about a lot in recent years because of certain effects it can have on us. The most worrying part is that studies have shown constant exposure to blue light over time can cause some serious damage to our eyes.
Before we get to the crux of the matter, it is necessary to note the effects of blue light on us. As mentioned, blue light exposure can be detrimental to us in the long run, but there are some good benefits as well.
Research has shown that blue light is indeed essential to our overall well-being. For one, it makes us feel more alert and is able to reduce our fatigue, making us feel more awake. Our circadian rhythm — the natural body clock in our body that regulates our awake and sleep cycle — needs blue light exposure to properly tune itself.
Another benefit would be assisting our memory and cognitive functions, where one study showed people who were exposed to more blue light within a week made fewer errors while working and had faster reaction times.
In the medical landscape, blue light is also effectively used to treat certain skin problems. Skin disorders like psoriasis and acne can worsen when certain cells cause the affected areas to become inflamed. Blue light has anti-inflammatory qualities and therefore alleviates the pain and destroys the harmful cells.
With the advent of the digital age, digital screen technology has evolved at a rapid rate. Many of the electronic devices we use nowadays use light-emitting diode (LED) backlit screens, and these LEDs are well-known to emit blue light. Now that we are becoming more digital-centric, almost everyone and anyone has a smartphone or computer, and that is how our exposure to man-made blue light is gradually increasing.
But why is this a bad thing?
For starters, we mentioned the circadian rhythm above. During the day, your body’s internal clock reacts with natural blue light from the sun and makes you feel awake by boosting your alertness. At night, the lack of blue light in your environment causes your circadian rhythm to make you feel tired, which is meant to help you fall asleep faster and get better rest.
However, now that you are constantly exposed to blue light at night thanks to the TV, computer, and smartphone screens, the natural rhythm gets thrown off balance as the blue light exposure causes your brain to perceive it as daytime. This is why nowadays, many of us find it difficult to sleep at night, and when we do fall asleep, it tends to be restless sleep, and as a result, we wake up in the morning still feeling tired and unrested,. The implications of this are fairly obvious — decreased alertness in the day makes us feel tired, and if we’re not careful, accidents can happen. Not to mention all the increased risks of developing cardiovascular disease, and conditions such as dark circles under your eyes.
As if that was not bad enough, there are other harmful effects too. Digital eye strain can lead to blurry vision and dry, irritated eyes, headaches, and neck pain. Studies have also shown that with prolonged exposure to blue light, it can contribute to macular degeneration — the ageing of the eyes which can lead to vision loss and blindness.
Fortunately, there are simple ways to reduce the exposure of blue light at night. Limit your usage of your devices — when you’re not working, and especially before bedtime. Most smartphones nowadays come with Night Mode installed — a special mode that calibrates the screen to minimize the amount of blue light emitted.
Nonetheless, it would be an even better idea to not use your devices at least 45 minutes before sleeping. So switch off your TV, put your phone away, and read a book instead. This way, you’ll always be refreshed and ready to get going in the mornings, and your eyes will thank you for it in the long run.