Blue Light and Screens

ANSES considers blue light as toxic to the retina and recommends limiting its use. The risk is the anticipated occurrence of AMD.

The dangerousness of the screens for the eyes is regularly treated by the media. "Screens, insufficient screening, bad practices ... Alert on the visual health of the French, and in particular the 16-24 years old", headlined 20minutes on June 20th. "Is blue light really bad?" . In 2018, Sciences et Avenir affirmed: "The blue light of the screens causes the self-destruction of the retina." And in 2017, https://www.lumiere-bleue.com announced: "Health: for your eyes, soft on the blue light".

In 2010, ANSES publishes a report on LED and blue light. This expertise "highlighted the retinal toxicity of the blue light present in LED lighting". LED light appears white in combination with a layer of phosphorus, yellow, says ANSES. But in the light emitted, the blue is well overrepresented.

In 2017, researchers from Inserm publish a study demonstrating the harmfulness of blue light for the retina of rats and children. In May 2019, ANSES updated its 2010 report by stating that the new data "show short-term phototoxic effects related to acute exposure and long-term effects related to chronic exposure, which increase the risk of age-related macular degeneration (AMD) "and" even a very low exposure to blue-rich light in the evening or at night disrupts biological rhythms and thus sleep ".

The fear around the blue light is to accelerate the appearance of AMD by damaging the retina, but without causing short-term consequences on vision.

The impact of light will depend in particular on the intensity of exposure and its duration. Thus, it is established that people who are more exposed to sunlight are more likely to develop AMD. The screens and the LEDs, they, expose to blue light with a lower intensity than the sun, but with a frequency of higher and higher. "The moment of exposure is also important. At night, our eyes are more sensitive to light. If we look at screens at night, we expose more our retina. Children are also a sensitive population because their crystalline lens, more transparent than that of adults, filters less light.

The importance of this phenomenon is nevertheless discussed. Thus, the ophthalmologists interviewed have quite different positions on the subject. One protects himself with anti-blue light filters on his glasses when others regret that we are worried about the light screens but we do not wear sunglasses on the beach .

"The definitive proof will come with epidemiological studies in 20 or 30 years, to see if the arrival of screens significantly advance the occurrence of AMD," said the president of the French ophthalmology company.

In the meantime, ANSES offers recommendations. The agency "recalls the importance of favoring" warm white "domestic lighting (color temperature below 3,000 Kelvin). It also calls for "limiting the exposure of populations, especially children, to the rich blue light of LED screens (mobile phones, tablets, computers) before bedtime and during the night."

And for filters and other protective glasses? The Agency "stresses that their effectiveness against the effects on the retina of blue light is highly variable. Moreover, their effectiveness in preserving circadian rhythms is not proven today. "

"They do not hurt, unless wearing pushes users to expose themselves because they think they're well protected."