French health watchdog warns on 3D usage for children
A French health watchdog has recommended that children under the age of six should not be allowed access to 3D content.
The Agency for Food, Environmental and Occupational Health and Safety (Anses) added that access for those up to the age of 13 should be "moderate".
It follows research into the possible impact of 3D imaging on still-developing eyes.
Few countries currently have guidelines about 3D usage.
According to Anses, the process of assimilating a three-dimensional effect requires the eyes to look at images in two different places at the same time before the brain translates it as one image.
"In children, and particularly before the age of six, the health effects of this vergence-accommodation conflict could be much more severe given the active development of the visual system at this time," it said in a statement.
It is not the first time questions have been raised about the safety of 3D, which is used in many feature films as well as on some video games, TVs and computer screens.
Italy has sought to restrict the use of 3D glasses by young children, following a similar warning from its national health agency last year.
When Nintendo released its portable 3D video games console in 2010 it warned that playing games on it could damage the eyesight of children under six.
The American Optometric Association has said that it has had no reports of eye damage as a a result of viewing 3D content.