How blue light disturbs your sleep? 3 tricks to minimize the negative impact

November 2, 2020
Reading time: 7min

Have you ever woken up to bright morning skies feeling energized? A big reason for your mood is the high-intensity blue light coming from the sun. Among the visible light spectrum, blue wavelengths have the most powerful effect on your sleep-wake internal body clock. At the same time, blue light can do much harm, especially when it comes to your eyes and body.


Have you ever woken up to bright morning skies feeling energized? A big reason for your mood is the high-intensity blue light coming from the sun. Among the visible light spectrum, blue wavelengths have the most powerful effect on your sleep-wake internal body clock. At the same time, blue light can do much harm, especially when it comes to your eyes and body.

The light is made up of different colors of light rays. While warm light contains more red wavelengths, cold light is mostly consisting of blue wavelengths, which in large quantities can have a negative effect on our eyes and our well-being.

What is blue light?

Blue light is a range of light spectrum, located in the most bottom part of visible light. Both blue and violet tones are called blue light.

Basically, blue light can be found everywhere. The most important source of natural blue light is the sun. At the same time, more and more blue light is coming from artificial sources – daylight lamps, ceiling lights, and all kinds of screens that emit higher doses of blue light, like computers, phones, and TVs.

While exposure to natural daylight is highly beneficial, artificial blue light make no good for our bodies. Too much exposure to blue light can keep you awake even when your body should actually wind down. This means, that when it’s getting dark outside, our bodies will usually start to prepare for sleep. But when we are sitting in front of the screen that emits blue light late at night, our brains will interpret it´s still time to be awake. Thus, the preparation for sleep remains short.

The reason why blue light can cause so much harm is that blue light has a short wavelength, which affects the level of melatonin, the sleep hormone, more than the others.

While normally the pineal gland in the brain starts releasing melatonin a few hours before sleep and melatonin reaches its peak at midnight, blue light is capable of increasing our alertness and mental sharpness regardless of the time of day.

Too much time behind the screens and blue light can lead to several health problems, such as:

  • dry eye syndrome
  • decrease in visual acuity
  • red eyes
  • tiredness
  • headache
  • neck and back pain.

How to minimize the negative effect of blue light

One 3-week study revealed that 20 individuals used either blue-light-blocking glasses or glasses that didn’t block blue light for 3 hours before bedtime. Participants completed sleep diaries during a one-week baseline assessment and two weeks’ use of glasses.

At the end of the study, the group who wore blue light blocking glasses experienced significant sleep quality improvement relative to the control group. Mood also improved significantly.

It´s important to point out, that exposure to natural blue light should never be limited. It´s the artificial blue light that should be reduced. Because blue light disrupts our body from preparing for sleep more than any other color.

As a growing number of people, including children, spend a considerable amount of time behind the screens day by day, screen time should definitely be controlled and limited, so that it could not make any more harm to our eyes. Also, this is necessary for our bodies, to wind down. In addition, there are more tricks to try, to support your body’s natural circadian rhythm.

blue light at night

Choose bulbs with a warm white tone

Because it is not just your phone or tablet. If you have cool-toned daylight lightbulbs installed in your bedroom or other rooms, it would be better to change them, to diminish the blue light.

When buying new bulbs, prefer the ones with the label “warm white” (2700 K). Today, also LED lamps come in warm white, in which the effect of visible light will remain neutral. Also, check your work lighting and desk lamp so that they won’t increase your dose of blue light during the day.

Lamps emitting blue light should definitely be avoided in children’s rooms. Compared to adults, children’s eyes are even more sensitive to harmful rays, and their daily amount of time under blue light and in front of various screens should be limited.

Put down your phone at least 2 hours before bed

Many people sit behind the screens late at night, watching TV shows, or just scrolling some news, or pictures posted by friends.

As the screens are one of the main sources of blue light, you should avoid this kind of activity at least 2 hours before your bedtime. This rule does not only apply to the phone, but the same goes for tablets, computers and TV. Instead, you can read some normal (printed) book.

Sometimes it’s good to give your eyes a little break, talk to your partner about your day or just go for a walk in nature instead. When you’re sitting on your computer, don’t forget to take a break in every hour. And please remember, this break is not meant for scrolling your phone, but for stretching and moving your body and for giving your eyes a rest.

Use blue light blocking glasses

Our eyes, and our bodies are not designed to spend time in front of screens throughout the day. If you must definitely complete some tasks on your computer or check your phone before bed, use special blue light blocking glasses, that will give your eyes protection and block the blue light. Also, such glasses are mandatory, if your work assumes you are exposed to blue light and/or sitting in front of screens all day.

Blue light blocking glasses look like regular glasses with special blue light blocking lenses. The blocking effect can also be achieved with a special coating.

Such glasses prevent the blue light from reaching our eyes, blocking both UVA and UVB rays and thus helping to prevent eyestrain. Since UV rays pose a real danger for our eyes, blue light blocking glasses can be worn both indoors and outdoors.

By using blue light blocking glasses, the negative effect of light emitted from screens can be diminished. These glasses also improve contrasts outdoors and protect us from blue light in the outdoor environment.

Blue light blocking glasses can be purchased from an eyewear store and you can also buy them with 0 lenses. This means that you can order them even if you normally don’t wear glasses, but you want to protect yourself from the blue light and make sure that UV rays can’t enter to your eyes.

As a reminder, reducing blue light exposure before bed is just a part of a healthy bedtime routine. For better transition into sleep, it is essential to take care of your sleep hygiene, minimize overall activity, stress, and work before bed, if possible. 

If you find yourself in front of the TV or the computer in the evening, protect your eyes from blue light with special glasses so that your circadian rhythm will not be disturbed. If there’s a lot of light in your bedroom, a face blanket or sleeping mask could help. Sometimes it’s just all about closing the curtains and changing the blanket and the pillow so that you could start to sleep better. The goal is to enjoy all the things that you find important during the day and not to worry so much about the health of your eyes, or the negative effects of blue light.