Some lamps diode, or LED, induce a risk for the eyes, especially among children. This is the conclusion of a study by the handles, which involves the color too blue and too high luminance. and among the different types of LED, most common are precisely the least safe
emitting diodes (LEDs) are increasingly present on the shelves. designated as ideal due to their low power consumption, they multiply in homes or workplaces and bloom in car headlights. yet their light differs quite significantly from other types of lighting and the usual standards suit them wrong. National Health Security Agency for Food, Environment and Labour (handles, born this year from the merger of afssa and afsset) conducted a study to assess the health effects of these LED . The working group met ophthalmologists, dermatologists, lighting specialists and physics of optical radiation. He also hosted the industrial lighting and scientists. Its findings, which have just been published in a report, cast a shadow over this fashionable lighting, which would not be without risk. two main effects are noted in the study: one of the wavelength and that of the luminance. the LED lights have a high proportion of blue light, that is to say short wavelengths.
Too blue light affects the retina is known that this color is a photochemical risk factor in the retina in the photoreceptors and the retinal pigment epithelium. Across the years, too severe exposure to such light may promote the degeneration of the macula, the central area of the eye with the greatest acuity. known as AMD (macular degeneration), the disease can progress to loss of central vision.
The aggravating effects of blue light on AMD and are strongly suspected from observations of convergent experimental models the report said. However, he added, these effects have not been demonstrated by epidemiological studies in humans, due to difficulties in assessing exposure and individual predispositions. we still know that excessive exposure to sunlight is a risk factor for AMD.
According to the study, the effect would depend on the type of LED. most of these lighting products are made from a pure diode emitting blue light (the diodes produce light over a narrow range of wavelengths), to which there is added a yellow phosphor for a lighting almost white .there are two other types (ultraviolet LED and phosphors; three diodes emitting in three colors), but the cost would be too high.
The study of the handles classified market lamps in four risk levels, from 0 ( no risk) to 3 (high risk). conclusion: it appears that some very commonly used in LED lights, signals and markings belong to the risk group 2 [moderate risk], while all other lighting sources available to the general public do not exceed the risk groups or 0 1. With these lights, sun and repeated exposure could therefore favor an appearance of AMD but no evidence is given. the report emphasizes that current standards do not allow to properly characterize this photochemical risk.
Luminance: up to a thousand times more than the glare threshold , however, the conclusion of the study reports of sensitive populations such as children, because their very transparent crystalline attenuates little blue light; individuals wearing artificial lenses (transparent crystalline like a baby); those without lens (aphakic). one must also add those more exposed through their work, lighting, for example.
The other effect highlighted by the study of the handles is that of glare, due to the enormous luminance LED. this luminance, measured in candelas per square meter (CDM2) indicates the amount of light emitted and related to the size (area) of the source. the LEDs are very bright and very small, so their brightness is high. we consider that a light source is comfortable up to 2,000 CDM2 and becomes dazzling over 10,000 CDM2. gold, some led tested in the study reached 10 million CDM2, a thousand times more The report provides a number of recommendations, starting with a restriction of led sales for the general public to allow only do LED with no more risk to blue light than traditional lighting. the report also recommends defining risk groups. Moreover, the study points out that it is not possible at the time of purchase, whether the LED is part of the risk group 0 or 1 or group 2