2014-11-06 06:21:41
The last ten years have seen the rapid development of new audiovisual technologies in stereoscopic 3D. After the significant increase in the supply of 3D films in cinemas since the mid-2000s, we are now witnessing the development of the supply of televisions, computers, game consoles, mobile phones and other equipment equipped with 3D technologies. The development of these technologies raises the question of their possible impact on health, and in particular on human vision, in the event of prolonged exposure, and especially for children and adolescents. Several manufacturers of devices equipped with 3D technologies have also issued warnings recommending that children avoid the use of these products.
In this context, ANSES issued an internal request to assess the potential health risks associated with the use of all 3D audiovisual technologies.
Visual discomfort that can lead to various symptoms
The analysis of the available scientific literature has identified various potential symptoms related to exposure to 3D audiovisual interfaces, resulting from visual fatigue due to “accommodation-vergence conflict”. Indeed, in the real world, to perceive depth and relief, the eyes converge (i.e. are directed towards the same object) and accommodate (the lens of each eye deforms to obtain a clear vision) at the same distance, i.e. at the distance of the observed object. The technique of stereoscopic restitution (in 3Ds) does not allow this physiological principle to be respected. The accommodation (on a screen for example) and the vergence of the eyes (on an object located in front or in the background of this screen) are thus not done at the same distance.
Visual fatigue can in particular result in peri-ocular fatigue and pain, the feeling of dry eyes, visual disturbances (double vision, reduced sensitivity to spatial contrasts, reduced visual acuity and speed of perception), extra-ocular disorders (headaches, neck pain, back and shoulder pain, reduced performance in mental activities, loss of concentration).
Other symptoms may potentially appear, in particular effects related to postural balance (vertigo) or effects related to the appreciation of reality (altered perception of the environment). However, these effects remain poorly studied, but might generate a one-time accidental risk related to dizziness.
In children, especially before the age of 6, more marked health effects related to the “accommodation-vergence conflict” of the eyes might appear, due to the active development of the visual system during this period (accommodation, vergence, maturation visual pathways, etc.), especially since the quality of 3D content, in terms of visual comfort, is very heterogeneous, despite the existence of technical recommendations.
The Agency’s recommendations
In this context, ANSES recommends:
- to advise once morest exposure to 3D technologies for children under the age of 6;
- that children under the age of 13 have moderate use of 3D technologies, and that they, as well as their parents, be attentive to any symptoms induced;
- that people subject to certain visual disorders (accommodation, vergence, etc.) and balance disorders limit their exposure to these technologies, particularly in occupational exposure contexts.
Given the lack of data concerning the exposure of the population to 3D technologies, ANSES recommends identifying the uses of 3D as well as the populations concerned, better characterizing the exposure of the different populations (adults, children and adolescents, professional users) and set up exposure monitoring.
The Agency also indicates that it is possible to limit visual fatigue or other symptoms in users of this type of technology. She recommends as follows:
- people experiencing symptoms when exposed to 3D interfaces to limit their exposure time and consult an ophthalmologist to screen for possible pathologies;
- not to position themselves too close to the screen: in fact, the further the spectator moves away from it, the less he experiences constraints on his visual system;
- to respect the instructions of the manufacturers of 3D devices;
- to keep its optical corrections when viewing 3D content;
- and that the creators of 3D content limit the effects produced by respecting the existing technical recommendations aimed at producing quality content;
Finally, ANSES encourages raising the awareness of early childhood medical and paramedical professionals and ophthalmologists of the mechanisms involved when viewing 3D interfaces. Thus, they will be able to inform parents of the symptoms and potential risks but also of the means to remedy them.
1692882288
#technologies #vision #recommended #children #moderate #children #handles
