New findings confirm earlier concerns that "exposure to an intense and powerful [LED] light is 'photo-toxic' and can lead to irreversible loss of retinal cells and diminished sharpness of vision," the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) warned in a statement.
The agency recommended in a 400-page report that the maximum limit for acute exposure be revised, even if such levels are rarely met in home or work environments.
The report distinguished between acute exposure of high-intensity LED light, and "chronic exposure" to lower intensity sources.
While less dangerous, even chronic exposure can "accelerate the ageing of retinal tissue, contributing to a decline in visual acuity and certain degenerative diseases such as age-related macular degeneration," the agency concluded.
Long-lasting, energy efficient and inexpensive, light-emitting diode (LED) technology has gobbled up half of the general lighting market in a decade, and will top 60 percent by the end of next year, according to industry projections.
LED uses only a fifth of the electricity needed for an incandescent bulb of comparable brightness.
The world's leading LED light-bulb makers are GE Lighting, Osram and Philips.
The basic technology for producing a white light combines a short wavelength LED such as blue or ultraviolet with a yellow phosphor coating. The whiter or "colder" the light, the greater the proportion of blue in the spectrum.
- Circadian rhythm -
LEDs are used for home and street lighting, as well as in offices and industry.
That are also increasingly found in auto headlights, torches (flashlights) and some toys.
LED cellphone, tablet and laptop screens do not pose a risk of eye damage because their luminosity is very low compared to other types of lighting, Francine Behar-Cohen, an ophthalmologist and head of the expert group that conducted the review, told journalists.
But these back-lit devices -- especially when they are used at night or in a dark setting -- can "disturb biological rhythms, and thus sleep patterns," the agency cautioned.
Comment: And the effects are far worse for children whose brains absorb up to four times as much radiation as that of an adult. For more info, see: The effects of smartphone light on your brain and body
Because the crystalline lens in their eyes are not fully formed, children and adolescents are particularly susceptible to such disruptions, the ANSES reports noted.
Interfering with the body's circadian rhythm is also known to aggravate metabolic disorders such a diabetes, as well as cardiovascular disease and some forms of cancer, noted Dina Attia, a researcher and project manager at ANSES.
In addition, a stroboscopic affect in some LED lights -- provoked by tiny fluctuations in electric current -- can induce "headaches, visual fatigue and a higher risk of accidents," the report said.
For domestic lighting, ANSES recommended buying "warm white" LED lighting, limiting exposure to LED sources with a high concentration of blue light, and avoiding LED screens before bedtime.
ANSES also said that manufacturers should "limit the luminous intensity of vehicle headlights," some of which are too bright.
Finally, the agency cast doubt on the efficacy of some "anti-blue light" filters and sunglasses.
Source: Agence France-Presse
Best approach IMO is to use the warm white mentioned as the default for all LED lighting, and throw away the 'daylight' pretenders and the blue as buggery stuff that fakes brightness with colour emphasis too high in the visual spectrum.
As for motor vehicle lights - too bright is never enough. We use dipped beams round here to lessen the problem - the French obviously have the dipper switch on the wrong side of the steering wheel:-)
The colour spectrum of quartz halogen is pretty close to colour correct as it's usually applied to headlights and driving lights - colours or surroundings aren't appreciably altered, so depth perception isn't a major problem, unlike the blue as buggery LED and HID lights.
And while I'm here commenting - a special place in hell is reserved for the MarketingJerks who believe a totally unnecessary very bright sprectral halo at the edge field of their vehicle lights is a necessary wank. My suggestion is to get rid of those idiots and their lighting products completely from the industry.
Of yes, I almost forgot - the likes of Toyota and VW are hard at it with speshul orange-ish Daylight Running Lights. Fine in the far northern origins of their designs..... butt.... It's the identical colour of many many Australian sunsets and some 'dawns', so they effectively camouflage vehicles oncoming out of the sun until you can literally read the front number plate. Too late then..Better no lights on at all to create a shadow in that circumstance. Just another torment for the long-distance driver - and the authorities wonder about the road toll - now there's some spin. A Toll - necessary deaths?
Just sayin'.