Screens: beware of blue light on the eyes

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Extract from the article: Everyone spends many hours a week in front of a screen: computer, tablet, TV, smartphone. But prolonged use of screens has an impact on vision. These tools emit blue light that is dangerous to health. How can you protect yourself?

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Everyone spends many hours a week in front of a screen: computer, tablet, TV, smartphone. But prolonged use of screens has an impact on vision. These tools emit blue light that is dangerous to health. How can you protect yourself?

Whether large or small, screens have become an integral part of our daily lives, almost indispensable. Here's what we heard on the streets of Djdjolé and Totsi in Lomé. « I spend a lot of time on my mobile. I can say about five hours a day. I can't get rid of it », says Reine, a student at the University of Lomé.  « For me, the cell phone means everything. Honestly, I can't imagine spending a day without it. One day I broke the screen of my mobile without realizing it, and that day I almost cried. It made me angry », admits Luc, a student in the second year of secondary school in the capital. The screens of laptops, computers and TV sets constantly emit blue light.

According to a report by France's Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES) entitled « Effets sanitaires des systèmes d'éclairage utilisant des diodes électroluminescentes », blue light is particularly harmful to sensitive individuals, including children and teenagers, and people suffering from certain eye and skin diseases. Consumers of photo-sensitizing substances, pregnant women, the elderly and migraine sufferers are also vulnerable.

Effects on the eyes

A scientific study published in the journal « Nature » in 2018 demonstrated that blue light, over the long term, can cause photochemical damage to the retina and crystalline lens. When emitted onto a particular molecule in the eye, it triggers a chain of chemical reactions that leads to the creation of particles toxic to photoreceptor cells.

« It's a part of the light visible to our eyes whose length is therefore between 180 and 500 nanometers. This is the light emitted by the sun, television, smartphones, computers and tablets. Being exposed to this light every time can have consequences that may or may not be remediable on our vision. These include ametropia, retinal lesions and crystalline lens damage », says Dr Doris Bohoun, Ophthalmologist at Hôpital Saint Luc in Cotonou, Benin.

Short or long-term exposure can lead to reduced vision, even blindness, visual fatigue and headaches. Even very low levels of exposure to blue light in the evening and at night disrupt biological rhythms and sleep.

How can we protect ourselves from blue light?

Limit the use of LED screens, phones, tablets, computers and TV before bedtime and at night. The screen emits blue light. This can inhibit the secretion of melatonin, the hormone that regulates a person's sleep/wake cycles. It's advisable to turn down the brightness of screens and take breaks if you're exposed to them for long periods.

Raymond DZAKPATA