Blue Light & Its Effect On Human Health

Blue Light

Did you know that the nifty electronic devices we use can have adverse effects on our health? Yes! Bright screens can dim your health. We use devices that depend on light-emitting diode (LED), which is why we are more exposed to blue light. Due to the exposure, not only our eyes are affected, but it can adversely affect our sleep patterns and our health.

In this article, we will discuss what is – and how it affects our well-being. 

What is blue light?

We are living in an electromagnetic world, where electromagnetic energy travels in waves. The electromagnetic waves can be identified by our eyes, even when they are invisible. The waves vary in length. The longer the wavelength, the less energetic the wave is, and vice versa. 

It is a visible light on the light spectrum that has a short wavelength. Due to the short wavelength, it contains more energy, so it is more harmful than the other lights. This type of light is almost as harmful as ultraviolet rays.

Harvard compared blue light and green light and concluded that blue light was twice as harmful as green light.

It’s not only transmitted through unnatural ways, such as your TV screens, tablets, mobile phones, etc., but we actually see blue light naturally, every time we look at the sky. The sunlight itself contains a lot of blue light, therefore, it is favorable to let the sunlight pass through your windows in the morning. It makes you less sleepy and more active during the day. During the daytime, it gives you the energy to function throughout the day. So exposure to blue light is recommended during the daytime, as it makes you more alert. It also reboots your circadian rhythm, so that you can fall asleep the following night. But too much of anything has its harms. Increased exposure to it can make your eyes fatigued.

Most people have been working on their laptops and desktops, for over a year, due to the pandemic. According to a study conducted in 2020, 93.6% of the population respondents reported that their screen time increased during the lockdown. Increased screen time means increased vulnerability to blue light.

Though, according to eye doctors, blue light does not harm the retina of a human eye. There is no evidence to confirm the damaging effects of blue light on the human retina. 


Let us talk about the health conditions for your eyes, where blue light is not necessarily the culprit. Eye strain is the most common problem. Digital eye strain is caused by constantly staring at the LED screens for longer intervals. The constant focus leads to eye muscle fatigue. When you’re focusing a lot on something, you don’t blink your eye. Not blinking your eyes as much leads to dryness. Less moisture in the eyes leads to irritation and a burning sensation in your eye.

When it causes your eye to strain, you may notice dry eyes, irritation, headaches, and tired eyes.

Age-related macular degeneration

When you age, sometimes the macula gets damaged. It is the central part of your retina, and if you lose your macula, you actually lose the central part of your vision. But it takes a huge amount of it to damage the central part of your retina. According to the research, the light we get from our screens is a lot less to cause significant damage. 

Sleep-wake cycle

It can affect your sleep-wake cycle. Light, in general, can delay the release of sleep hormones, especially blue light. Do you experience those nights when it is hard for you to sleep? Well, that is because of the blue light emitted from your phones or television screens. At night our brain releases a sleep hormone, melatonin, which helps us fall asleep at night and stay asleep through the night. So if you are exposing yourself to a lot of blue light at night, it will send a signal to your brain that can affect your body’s production of melatonin hormone. It will make you less sleepy, which is not well for your health. 

Melatonin disruption can cause an imbalance in the production of hormones in your body, which can affect your overall health and well-being. There is an increased probability of hormone-related cancers. It may cause a lack of leptin, which might lead to obesity as your body will not signal when you are full after eating. In addition, there can be metabolic changes, especially in blood sugar levels.

Benefits of blue light

  • However, there are benefits of exposure to blue light as well. Blue light can make you alert when you are feeling lazy. It would signal your mind, that it is time for action. 
  • According to a study, the people exposed to blue light had a better verbal memory, and they performed tasks very well.
  • According to research, it is also concluded that blue light can work for treating seasonal depression when combined with medications.
  • If you’re among the people who experience frequent acne, blue light can be used for treating your acne as well. If you have breakouts, it can reduce inflammation.


You may take some precautions to minimize the negative effects of blue light on your health:

  • Stay at least two feet away from the screen of your computer.
  • Use eye lubricating drops if you have to stare at your computer screen for a very long amount of time. This will keep your eyes moist.
  • Use the 20/20/20 strategy. After every 20 minutes, stare at a point that is 20 feet away, for at least 20 seconds. This will allow your eye muscles to relax so that you can regain your focus.
  • Turn around your sleep habits, and shut off your screen at least two hours before bed. If you are unable to sleep without screen time, change your screen’s light color. Turn your screen on the ‘night-shift mode.