All You Need to Know About Blue Light and Its Impact On Your Health

Today, we are exposed to artificial blue light more than ever. Scrolling through social media, staring at the computer during office hours and watching TV shows on Netflix – the time we spend on screen can go as high as a dozen hours. Unfortunately, being overexposed to blue light can potentially harm your health in many ways. This article will explain why screen time can negatively impact our health and what we can do about it. 

What is blue light? 

Let's first understand what blue light really is. Sources of blue light are all around you – the sun, the lights in your room and your electronic devices, and we are exposed to it daily. We are surrounded by electromagnetic energy, which travels around us through waves. Large-spectrum waves, such as x-ray or radio waves, cannot be detected by the human eye, while a small band of waves, known as visible light, can be seen by human beings. So, is blue light actually harmful per se and what should we know about it? 

How does blue light affect your health? 

It is important to understand that, in fact, human beings need natural light to stay healthy and energetic. Balanced exposure to sunlight is vital for our immune system, mood and circadian rhythm – a biological clock in our bodies that tells us when it's time to sleep or wake up. The challenge here, however, is to maintain the right balance. Centuries ago, before the widespread emergence of electronic devices, sunlight was the only source of blue light. It was easy to follow the natural day and night light exposure cycle. However, with the technological advancement of the modern era, our lives constantly revolve around electronic devices based on light-emitting diode (LED) technology with high amounts of blue light. For that matter, overexposure to artificial blue light may pose several health risks.

Blue light and sleep

As mentioned above, each of us has our circadian rhythm, which determines when our bodies need to sleep and wake up. Importantly, circadian rhythm and light are closely connected. During the day, blue light is vital for us, as it makes us energised and increases our cortisol levels. Vitamin D that comes from the sun is great for our immune health and mood, as well. However, it's time for our bodies to gradually prepare for rest after sunset. Only during the night, our brain produces a sleep hormone, melatonin, which helps us maintain healthy sleep and go to rest mode at night. Therefore, the natural light cycle is extremely important for our body clocks. 

Unfortunately, when we expose ourselves to blue light in the evening, our biological clocks might experience dysfunction. According to a study published in the journal of Biological and Medical Rhythm Research, evening light exposure from electronic devices may lead to sleep disorders and disrupt our circadian rhythms. Another study by Harvard researchers revealed that blue light suppresses melatonin production twice as much as other light sources. That includes electronic devices and LED lights widely used in households for their energy-saving characteristics. It is important to avoid extra screen time before going to bed to maintain a healthy biorhythm. 

Blue light and mental health

Maintaining a healthy circadian rhythm is also vital for your mental health. Balanced exposure to natural blue light – sunlight – during the day is highly beneficial for mental health and mood. That is why we tend to be happier in the summer when days are longer and are more likely to fall into the blues in winter when days are shorter. Nevertheless, again, it all comes to balance. Suppose we disrupt our circadian rhythms by spending too much time staring at our phones or laptops before bedtime. In that case, we may experience a loss of focus and a lower mood. Research shows that the disruption in the circadian rhythm may affect hormone secretion, your brain's neuroplasticity and the formation of new neuro signals. Thus, paying attention to your sleep quality is necessary to maintain healthy cognitive function and mood. 

Blue light and eye health

To protect itself from the damaging effects of light, your eye structure consists of a cornea and lens. However, overexposure to blue light poses a risk to the retina at the back of your eye. Looking at the sun with its damaging UV light is considered risky for your eyesight, so wearing shaded sunglasses is recommended. However, staring at LED-technology-based electronic devices raises even more concerns than being out in the sun without sunshades. While we may glance at the sun for only a short moment, we stare at our phones or laptop screens for hours, as the distance between our eyes and screens is also very small. For that matter, research suggests that increased screen time may cause digital eye strain and even possible damage to the retina. In particular, researchers and doctors are concerned about children as their eyes can't filter blue light like adults' eyes. It is, therefore, advised for parents to monitor their children's screen time and encourage conscious technology use. 

Tips to improve your blue light exposure 

  • Use eye drops when you work on the computer for long hours – it will improve the symptoms of dryness and eye irritation. 
  • If you have to work in the evening, adjust your screen to "night shift", which is warmer in colour.
  • Monitor your children's screen time and teach them conscious technology use – no screen time before bedtime and encourage more outdoors activities.
  • Use the 20-20 technique to relieve your eyes – that means, every 20 minutes, you should stare 20 feet away for at least 20 seconds. 
  • Wear sunglasses to avoid damage by UV light, as per American Ophthalmology Association recommendations
  • Avoid screen time at least one hour before going to bed. We know we all like to scroll through our social media feed or fall asleep with the TV on. However, avoiding overexposure to blue light from devices is beneficial for a healthier sleep schedule. 
  • Extra tip: if you have difficulty falling asleep without your social media bedtime routine, try to go for an audiobook or a podcast instead. You can adjust the playtime to a specific timeframe so that the track will shut down automatically when you fall asleep. 

Author of the publication

Polina Kuznetsova
Polina Kuznetsova
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