The LED technology is needed today in fixtures, garlands of decoration, torches, highlight car, but also in computer screens and smartphones. Rich in blue light, this lighting worries ANSES (National Agency of Sanitary Security) which published a report on the subject, in May 2019.
How do LEDs attack the eyes?
The blue LED light has a short wavelength, very energetic. This intense flow attacks the cells of the retina and disturbs the secretion of melatonin, the sleep hormone, dependent on variations in natural light.
“The retina can withstand a certain amount of light, but at some point its repair capabilities are out of date,” says Dr. Alicia Torriglia, research director at Inserm.
But in the history of humanity, the eye has adapted to a “warm” lighting, especially in the evening: the fire, the candle, then the incandescent lamps. With LEDs, you have to tolerate a much colder “blue” light. For the retina, it’s not ideal.
Security standards frame theDomestic lightingbut not toys or torches. In addition, the current limit values calculated for exposure of less than 8 hours a day “do not take into account chronic exposure to LEDs, every day and over several years,” says Professor Francine Behar-Cohen, professor in ophthalmology .
Who are the most sensitive?
- The children : their lens, this lens which filters the light rays and directs them towards the retina, is transparent. It lets more blue light pass than that of an adult. However, long-term exposure to strong light increases the risk of age-related macular degeneration (AMD). In addition, children spend a lot of time on the screens at the risk of disrupting their sleep.
- Seniors : with age, the eye becomes more sensitive to light and glare. Too much blue light could cause “premature aging of the retina,” according to Dr. Torriglia who points to a potentially increased risk of AMD.
- The migraine and the epileptics : The luminous level of the LED bulbs fluctuates in a more or less noticeable way. This flicker can cause headaches, even an epileptic fit. However, according to the ANSES report, “approximately 43% of domestic LED lamps have degraded performance” in this area.
- The pregnant women : Studies in animals have shown that exposure to blue light, during pregnancy, disrupts the fetal circadian rhythms, hence its development. “We do not advise pregnant women to be on screen at night,” says Pr Behar-Cohen.
- Patients suffering from a pathology of the eye: when the crystalline lens or retina is reached, it is less resistant to light aggression.
- Some professionals: night work and some trades (lighting, dentist, surgeon …) expose to artificial lighting for long hours.
What to do against the blue light of LEDs?
- Avoid LED toys and blue decoration lamps (garlands, night lights …).
- Let the children play as much as possible in the light of day. The more time they spend outside, the less likely they are to be nearsighted.
- Turn off his screens, ideally, 2 hours before going to bed and do not use your smartphone or tablet in the middle of the night.
- Download the free software F.lux which reduces the blue light of screens in the evening. Some models of computers or tablets do this automatically. The anti-blue light glasses are not all effective. There is no standard to prioritize them.
How? ‘Or’ What choose his bulbs ? The “color temperature” of a bulb indicates its amount of blue light. It must not not more than 3000 K (Kelvin). It is better to choose those that are marked “warm white”.