What is blue light and how does it affect our vision?

what is blue light

Nowadays, all electronic devices emit blue light, and the use of digital devices becomes essential in the daily activities of most of the people, either it is a smartphone screen, televisions (Les screens), computer screens, or tablet. Too much exposure and the persistent staring at screens and the dangerous ”blue light” emitted from those latter will harm the ocular health. However, we are wondering if this light is harmful? Does it really affect eye health with persistent staring?

1. What is blue light?

The visible spectrum is consisting of seven various waves, namely red, orange, yellow, green, blue, dark blue, and purple, those gathered waves form the white light that we see. Each wave has a distinct power and a different wavelength; the longer the wave light increases its power decreases. The blue light has a short wave, consequently a high power. The light must contain a big amount of blue light to look white.

The blue light used to illuminate the digital devices’ screens, especially the laptops, because they consume a small amount of power “electricity” than the luminous standard lamps and because it makes the screen brighter, which facilitates the vision during the day and under the sunlight.

2. The sources of blue light

The source of this light is not restricted only to screens. The sun is considered as the big source of it, and the other sources are; Fluorescent lamps and low power lamps, which emit blue light more than the standard lamps.
The rate of the blue light that the screens emit is considered small compared to that from the sun, but the screens are closer to the eye. Besides, staring at screens is not only during the day, but it lasts throughout the day.
Some studies state that the effect of the blue light on the eye varies according to the age difference; for example, the children’s eyes are more delicate and sensitive to this light than adults, so the children’s staring at screens is more affecting than others.

3. The advantages of blue light

Despite the continual warnings of the harmful effects of blue light, the exposure to it and especially the one that the sunlight emits has many benefits, such as:
Being vigilant and active
Memory support and help to focus attention
Improve the mood
Organize the biological clock (sleep/wake cycle)
A new study states that the children who don’t receive enough of this light during the day affects eye health and eye development and their vision and may lead to myopia.

4. Disadvantages of the blue light

Although the general belief which states that the extended light exposure of the screens, affects the eyes or lead to Macular Degeneration or blindness, however, many new studies find that this amount of blue light is not enough to such harm. Still, it is less than the one we are every day exposed to outside. The same study indicates that the light which the economic lamps at home emit during the night is almost two times more than the one from the digital devices’ screens.

Also, a study indicates that the discomfort or the pain that may hit the eyes after prolonged staring at screens is what we know as digital eye strain and which occurs because the long staring at screens leads to blinking for several times more than usual and this which causes dry eyes (dehydration) and eye fatigue.
Therefore, we advise to reduce the use of digital devices as possible, avoid too much exposure to screens, take breaks, and use eye drops to hydrate the eye.

Although the blue light is not acquitted from accusations, studies show that the exposure to this light during nighttime causes troubles of the natural sleep/wake cycle of the body. This leads to difficulties of sleeping, insomnia, and the sensation of fatigue; therefore, we advise not to stare at any screen at least two hours before bedtime, moreover, restrict the amount of light of digital devices’ screens at night.

5. Blue light glasses

Anyone exposed to this blue-violet light for more than 30 minutes a day could benefit from these glasses. Almost everyone! In any case, if you spend the day in front of a screen and especially if you like to walk outside, it is highly recommended. Besides, specialists advise making cures of 3 months of food supplements for the eyes from 40 years (based on lutein, vitamin E, zinc, antioxidants), to repair photo trauma.
If you have a family history of AMD or cataracts, we highly recommend that you take these blue light-proof glasses. Please note, however, that not all glasses are created equal: the different existing models do not all filter the same percentage of toxic light.


The omnipresence of screens is an integral part of modern life; and removing, or even limiting their use seems complicated and, in any case, completely illusory. You should not take eye health lightly …
What we can do, however, is to take all possible protective measures and instill in our children good reflexes. Because young people who are exposed from an early age, are the most concerned by the risks of blue light, their lens being transparent, unlike adults who have a more yellow lens which filters blue light better.

Finally, the solution is not so complicated or expensive: we just need to favor the screens that expose us the least to this light, to follow some advice to reduce eye fatigue and to equip us with protective glasses quality. Compared to the risks involved, the game is well worth the effort!

Originally published on Live Positively.