The French Agency for Food, Environmental and Occupational Health and Safety (ANSES) said that long-term exposure to light at the blue end of the spectrum – especially light from LEDs – can cause ‘toxic stress’ to the retinas. A photochemical change in the eye – related to the amount of retina exposure to blue light – can result in what’s termed cellular oxidative stress, said the authors of the report.
Vulnerable groups include children, those with high photosensitivities, and those who work in high lux levels.
The report also criticised LEDs for their high glare. It pointed out that, because LEDs are point sources, they are more liable to exceed acceptable glare limits. It recommended that the Unified Glaring Rating should be dropped for LED sources because it is unsuitable.
ANSES said LED lighting manufacturers should use optics or diffusers to ensure that the light emitted by the LEDs cannot be seen directly. It also suggested they should take account of the progressive wear of layers of phosphor in white LEDs, which in time could make the devices a higher photobiological risk.
‘Obviously this report is concerning,’ said LIF CEO Eddie Taylor. ‘More research is clearly needed to corroborate these conclusions and see how we can work with our European partners on standards bodies to make LED lighting systems as safe as possible and, if necessary, issue guidelines on the use and manufacture of LED products.’