Blue light: how to protect your eyes?
Blue light is more and more talked about because it is emitted by the ubiquitous screens every day. Are we really more exposed? Is blue light a real danger to the eyes? Should we be equipped with anti-blue light glasses when we use a lot of screens? Answers from specialists.
Part of the spectral light can be dangerous for our retina. To protect ourselves from some of the light emitted by our screens, anti "blue light" glasses have emerged. What are they useful for?
Blue light is a part of the spectrum of light, whose wavelengths are between 380 and 500 nanometers. It is emitted by the sun, but also by artificial light sources: LED bulbs and screens (tablets, televisions, computers, smartphones).
The potentially dangerous blue light represents only a small part of all the existing blue light: these are the blue-violet wavelengths. "The spectrum of daylight or artificial light includes colored stripes, among them, turquoise blue, a light that is good for morale, and then blue-violet, a light to which we are increasingly exposed", says Dr. Petra Kunze, an ophthalmologist in Paris.
In fact, the energy reaching the retina in the case of the blue-violet light is stronger than in the case of the turquoise blue light. The screens especially diffuse peaks of blue light called High Visible Light (or HEV).
In 2014, the French spent an average of 6 hours in front of a screen. It is estimated that a child born in 2015 will have reached the age of 7 the equivalent of a full year, day and night, to scan a screen. "In addition to that, the ozone layer no longer plays its role as a solar filter," says Dr. Kunze.
Here we are overexposed to this blue light, and that from the youngest age. This is not without consequences for our eyes. Especially in children under 14, whose lens of eye does not filter as well and for whom this blue light is even more harmful.
"It has been demonstrated on an in vitro model of age-related macular degeneration (AMD) that the most toxic wavelength for retinal cells is around 415-455 nanometers," explains Professor Serge Picaud, neurobiologist and director Inserm at the Institute of Vision 1. This phototoxic zone corresponds to a blue-violet light in the rainbow spectrum.
Scientific research has concluded that prolonged exposure to blue light radiation or artificial HEV light causes photochemical damage to the retina and lens. "Several epidemiological studies have shown that this blue light is a risk factor for AMD, " recalls Professor Serge Picaud. 2,3 The involvement of blue light in the development of cataracts is also suspected.
However, blue light can also have beneficial effects. It helps our circadian rhythms (sleep/wake alternation) and our mood. This time, it is the turquoise blue light (around 490 nm) that allows recalibrating our rhythms during a jet lag. The latter regulates the production of melatonin, our "sleep hormone".
In France, several brands have recently been offering "selective photoprotection" lenses, in other words spectacles whose lenses have a filtering treatment. Their principle? Protect the eye from toxic light wavelengths for the retina. These glasses filter the blue-violet light but let pass the turquoise blue light, in order to preserve the beneficial effects of the latter on the vision and the regulation of the internal biological clock. These glasses have a slight reflection, obviously purple.
What about their effectiveness? "The demonstration of their effectiveness was made in vitro and is not quantifiable for humans in the current state of work," says Jean-Manuel Finot, optician 1. "These glasses block a significant part of the light among wavelengths identified as toxic to the retina, so we can assume that there is real protection of retinal cells," adds the neurobiologist Professor Serge Picaud.
"All people exposed to this blue-violet light for more than 30 minutes a day could benefit from these anti-blue light glasses," Dr. Kunze recommends. 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," adds the ophthalmologist. The specialist advises, in addition, to make cures of 3 months of food supplements for the eyes from 40 years (with lutein base, vitamin E, zinc, antioxidants ...), to repair photo trauma.
"If you have a family history of AMD or cataracts, it is highly recommended to bring these anti-blue light glasses," says optician Jean-Manuel Finot. Be careful, however, not all glasses are equal: the different existing models do not filter all the same percentage of toxic light.
There is no contraindication to wearing these anti-blue light glasses. "The only limiting factor is that these glasses prevent the blue light from reaching the retina by reflecting it, resulting in a residual reflection, unattractive to the taste of some", says Jean-Manuel Finot. However, these eye protectors should still make progress in the future. "We can hope for more protective glasses," says Professor Picaud, whose team continues to work on this subject.
Side price, it takes between 35 and 50 euros per glass for a pair of glasses filtering blue light without correction, for people under 40 years with no visual problem. An additional cost per lens will depend on your correction if you have corrective glasses.
And as another protection track? "In the future, it would also be useful for all screens to have built-in filters, just like light bulbs," says ophthalmologist Dr. Petra Kunze. An effective way to protect the vision of the entire population without the need for more glasses.
Part of the spectral light can be dangerous for our retina. To protect ourselves from some of the light emitted by our screens, anti "blue light" glasses have emerged. What are they useful for?
Blue light, what is it?
 |
| Buy Now |
The potentially dangerous blue light represents only a small part of all the existing blue light: these are the blue-violet wavelengths. "The spectrum of daylight or artificial light includes colored stripes, among them, turquoise blue, a light that is good for morale, and then blue-violet, a light to which we are increasingly exposed", says Dr. Petra Kunze, an ophthalmologist in Paris.
In fact, the energy reaching the retina in the case of the blue-violet light is stronger than in the case of the turquoise blue light. The screens especially diffuse peaks of blue light called High Visible Light (or HEV).
In 2014, the French spent an average of 6 hours in front of a screen. It is estimated that a child born in 2015 will have reached the age of 7 the equivalent of a full year, day and night, to scan a screen. "In addition to that, the ozone layer no longer plays its role as a solar filter," says Dr. Kunze.
Here we are overexposed to this blue light, and that from the youngest age. This is not without consequences for our eyes. Especially in children under 14, whose lens of eye does not filter as well and for whom this blue light is even more harmful.
Blue light, dangerous for the eyes
 |
| Buy Now |
Scientific research has concluded that prolonged exposure to blue light radiation or artificial HEV light causes photochemical damage to the retina and lens. "Several epidemiological studies have shown that this blue light is a risk factor for AMD, " recalls Professor Serge Picaud. 2,3 The involvement of blue light in the development of cataracts is also suspected.
However, blue light can also have beneficial effects. It helps our circadian rhythms (sleep/wake alternation) and our mood. This time, it is the turquoise blue light (around 490 nm) that allows recalibrating our rhythms during a jet lag. The latter regulates the production of melatonin, our "sleep hormone".
The effectiveness of anti-blue light glasses
"There is no real protection, except to put filters between light sources and our eyes," says Dr. Petra Kunze. There are anti-blue light filters for screens, but not widespread.In France, several brands have recently been offering "selective photoprotection" lenses, in other words spectacles whose lenses have a filtering treatment. Their principle? Protect the eye from toxic light wavelengths for the retina. These glasses filter the blue-violet light but let pass the turquoise blue light, in order to preserve the beneficial effects of the latter on the vision and the regulation of the internal biological clock. These glasses have a slight reflection, obviously purple.
What about their effectiveness? "The demonstration of their effectiveness was made in vitro and is not quantifiable for humans in the current state of work," says Jean-Manuel Finot, optician 1. "These glasses block a significant part of the light among wavelengths identified as toxic to the retina, so we can assume that there is real protection of retinal cells," adds the neurobiologist Professor Serge Picaud.
Anti-blue light glasses: who is concerned?
 |
| Buy Now |
"If you have a family history of AMD or cataracts, it is highly recommended to bring these anti-blue light glasses," says optician Jean-Manuel Finot. Be careful, however, not all glasses are equal: the different existing models do not filter all the same percentage of toxic light.
There is no contraindication to wearing these anti-blue light glasses. "The only limiting factor is that these glasses prevent the blue light from reaching the retina by reflecting it, resulting in a residual reflection, unattractive to the taste of some", says Jean-Manuel Finot. However, these eye protectors should still make progress in the future. "We can hope for more protective glasses," says Professor Picaud, whose team continues to work on this subject.
Side price, it takes between 35 and 50 euros per glass for a pair of glasses filtering blue light without correction, for people under 40 years with no visual problem. An additional cost per lens will depend on your correction if you have corrective glasses.
And as another protection track? "In the future, it would also be useful for all screens to have built-in filters, just like light bulbs," says ophthalmologist Dr. Petra Kunze. An effective way to protect the vision of the entire population without the need for more glasses.
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