These glasses that filter the blue light from the screens are fashionable among opticians.
- Are they effective?
- Do they really reduce eye fatigue?
- Why is the blue light special?
- The toxicity of blue light is real, but often oversold.
- Only certain screens are a problem for the eyes
- These goggles only filter out some of the blue light...
- Blue light glasses may reduce visual fatigue.
- No, these computer goggles don't protect against AMD!
"Screens tire our eyes", they're "harmful"... Manufacturers are trying to convince us to buy glasses to protect us from the light emitted by our screens, especially the blue one. It is true that we spend an average of 5 to 7 hours a day in front of our smartphone, computer, tablet screens... Enough to raise a few concerns for our eyes.
Does the blue light blocking glasses really work ?
Why is blue light special?
Blue light is a blue-violet light of certain wavelengths, from 415 to 455 nanometres. They are more energetic than others, and strike the retina with greater power. Blue light is found everywhere, including in natural light. But OLED screens have proportionally more. Indoor lighting LEDs too, which is why specialists recommend buying "warm white".
The toxicity of blue light is real, but often oversold.
The effects of blue-violet light on retinal cells have been demonstrated:
In 2013, a study by the Vision Institute showed that blue-violet light could destroy pig retinal cells, causing damage comparable to that of age-related macular degeneration (AMD). However, this finding was made under experimental conditions that have little to do with reality.
"We don't know what the effects of dark blue light are in real conditions, but it is certainly toxic, especially in children whose corneas and clearer lens allow almost all the blue to pass through,"
Says Professor Gilles Renard, scientific director of the French Ophthalmological Society. Repeated exposure could have cumulative effects over time, creating a potential long-term risk. So only the youngest are really concerned.
Only certain screens are a problem for the eyes
In everyday life, our screens can expose us to blue-violet wavelengths, it's true, but not all of them. Only the most recent LED technologies produce a light spectrum composed of more blue light than natural light, and not all of them are equivalent.
"LCD screens lit by diodes are not a problem," says Professor Renard. Because the light passes through the liquid crystal panel, and is not transmitted directly to the user. Conversely, in OLED or AMOLED displays, each diode is on the surface of the screen, and the closer you look, the more light you receive. It is therefore preferable to limit the exposure time and keep them as far away from the eyes as possible."
These glasses only filter out some of the blue light...
Their lenses are made of the same materials as corrective lenses, mostly synthetic resin. They then receive a treatment that reflects some of the blue-violet waves and prevents them from penetrating the eye.
Opticians promise to stop 30% to 40% of all blue light. According to Professor Renard, this benefit is overestimated:
"They do not filter all the problematic wavelengths, and they only manage to stop about 20% of those they attenuate: this is very insufficient to be able to claim to protect the eye."
Blue light glasses may reduce visual fatigue.
This is the second medical argument put forward with which ophthalmologists disagree: "The computer is a revealer," explains Prof. Souied, an ophthalmologist.
- Periorbital pain at the end of the day
- Visual troubles
... It means you probably have an uncorrected visual defect. You compensate by straining your eye muscles, which causes fatigue. "In this case, the only thing to do is to make an appointment with your ophthalmologist.
However, when you spend long hours in front of the computer, concentration can slow down the blink rate, causing discomfort and irritation. In this context of dry eyes, blue light glasses may provide some comfort. This is what some testimonials on the forums of websites describe.
It is not impossible, but not proven: the hypothesis is being tested, it is not yet proven. Of course, it is also possible to solve the problem by obtaining artificial tears, by taking care to vary the positions of the glance, and to place the screen slightly below so as not to widen the eyes. But it's not as pretty as a pair of glasses.
No, these computer glasses don't protect against AMD!
Some ambiguous advertisements suggest that blue light glasses can protect us from AMD, which is characterized by a black spot in the middle of the visual field. Professor Éric Souied, a specialist in AMD, is quite excited about this: "It's a marketing argument! No glass can protect against this 70% genetic disease. »
Instead of buying glasses, it's better to... quit smoking. "It's the main modulating factor in AMD, increasing the risk by four to six times," he says.
So, in conclusion: do blue light glasses really work ?
Yes, and no.
👉 Blue light glasses really work when you use them at night, to reduce the intensity of the screens and get the most out of your sleep hormones.
👉 On the other hand, blue light glasses don't really work for AMD.