Early warnings about 3D video may have been overreached, but young eyes still need time away from the screen.

RODALE NEWS, EMMAUS, PA—At the Consumer Electronics Show in Las Vegas last week, three-dimensional technology was reportedly everywhere—television companies, movie studios, video game manufacturers, all promising a 3D experience. Yet as much as these manufacturers hope consumers will jump on the 3D bandwagon, some of those same manufacturers are warning a segment of their user base to stay away. In a somewhat unusual move, Nintendo issued a warning in December telling parents that children under 6 shouldn't use their soon-to-be-released 3DS video game system because of the potential impact it could have on children's eye health. Since corporations are usually not so forthcoming about possible health problems related to their wares, the warning raised eyebrows in both the medical community and among gamers.

THE DETAILS: Nintendo's warning stated that 3D technologies of all sorts, not just those related to its 3DS, could have a potential impact on eye growth in children under the age of 6. And the popular game maker isn't the only company issuing warnings. The television maker Samsung issued a warning with its 3D sets last April, suggesting that pregnant women, the elderly, people with certain medical conditions, and "those who are sleep deprived or under the influence of alcohol" should stick with 2D TV. The company has since toned down those warnings, but still maintains that "A responsible adult should frequently check on children who are using the 3D function. If there are any reports of tired eyes, headaches, dizziness, or nausea, have the child stop viewing 3D TV and rest."

WHAT IT MEANS: Because the technology is so new, there haven't been any medical studies on 3DS's effects on people to support these warnings. The American Optometric Association and the American Academy of Pediatrics have released statements saying such precautions aren't necessary. In a recent Wall Street Journal article, the president of Nintendo admitted the warning was a "proactive measure" and that the company was being overly cautious.

"I think the reason they're concerned is that a developing child's visual system is fragile and can be disturbed by certain conditions in ways that can be permanent," says David Hunter MD, PhD, clinical correspondent for the American Academy of Ophthalmology and the ophthalmologist-in-chief at Children's Hospital Boston. Often, problems with a child's vision are caused by other factors and can come on suddenly, he adds, and the ubiquitous nature of video games makes them easy targets for parents and lawyers. "I often see a child that's fine one day and the next day their eyes are crossed," he says. Other kids can have perfectly good vision in one eye and be blind in another, which parents won't know about until a child is tested. "With millions of games out there and all this new technology, you can imagine the tendency to blame it on the device," he says. And in a litigious society, that makes companies like Nintendo and Samsung nervous and inclined to cover their bases.