Next month Nintendo's 3DS finally rolls off assembly lines and into the hands of gamers around the world. The advent of "go-anywhere, glasses-free 3D" is nearly here. But with it come questions about 3D's safety, especially for children under the age of seven, whose eyes may still be developing and susceptible to techniques that alter the way our eyes capture two discrete images for the brain to render as one in 3D.
Last month the American Optometric Association issued a statement suggesting kids six and under can play Nintendo's 3DS as long as their visual system is developing normally. But 3D TV manufacturer Samsung has cautioned that "children and teenagers may be more susceptible to health issues associated with viewing in 3D and should be closely supervised when viewing these images." And Nintendo itself has warned that "very young children not look at 3D images...because...the muscles for the eyes are not fully formed."
What to make of these red flags?
To get answers, we spoke with VSP optometrist Dr. Nathan Bonilla-Warford, chair of the Children's Vision Committee of the Florida Optometric Association, as well as a Fellow of the American Academy of Optometry.
Game On: What should we make of recent claims by Nintendo and some 3DTV manufacturers that young children shouldn't look at 3D images?
Dr. Nathan Bonilla-Warford: 3D technology can be visually stressful. And there is more concern about children using 3D technology than adults, because children have not fully developed their visual skills. 3D video games can cause the eyes to work much harder than usual, making it more difficult for the eyes function. Children generally are less aware of their eyes so they are less likely to know if they are having visual problems. This is especially true with something very engaging like 3D games. Even if they do know, children may be reluctant to discuss 3D symptoms with parents because they fear the 3D may be limited or taken away.
GO: Does the 1960s research that concluded our eyes are still developing during a "critical period" through about age seven still apply today?
NBW: The research done in the 1960s was a very big step to understanding visual development, however in recent years there have been quite a few revisions concerning the concept of "critical periods" and their influence on visual development. Unfortunately I don't think this research really applies to the question of 3D technology. We don't really know exactly how these technologies would affect children and their visual development, but it is safer to say that the more intensely they are used, the more likely there will be an impact.
GO: The 3DS employs autostereoscopic technology, but it's just one of several ways of achieving stereoscopic 3D. Are some 3D techniques better or "safer" than others?
NBW: All of the different 3D techniques are essentially achieving the same goals through different means. Every 3D technology at its core is presenting each eye with different images. In the case of artificial 3D, the way the eyes coordinate, align and focus in everyday life are different compared the real world.
The Nintendo 3DS system is different than 3D TVs and 3D films. The closer you hold or view the 3D system, the more strain it will put on the convergence and focusing system of the eyes. This applies to both 2D and 3D images. Therefore the strain of watching a 3D TV, which is ideally 10 feet away, or 3D films, which are much further away, is less intense for the eye systems. It is in this way the Nintendo 3DS is inherently less safe and more likely to cause 3D symptoms like fatigue, nausea, headaches, dizziness and eyestrain.
Furthermore, the ways in which 3D is generated can be designed to be more natural or tolerable than others. In the case of Avatar, the filmmakers specifically tried to make the 3D effects more natural and lifelike for viewers. It remains to be seen whether or not the video effects from 3DS and other upcoming devices will have the capability in the small screen to take advantage of the natural 3D effects.
The one thing about the 3DS that particularly interests me is the 3D volume, which allows the viewer to turn down or turn off the 3D feature. This aspect of the 3DS does make it a little bit safer because if symptoms begin to appear, you can simply turn off the 3D and play in a 2D format.
GO: What about adult use? What concerns are there about adult eye interaction with 3D technology, if any, from an ophthalmological standpoint?
NBW: Adult visual systems are much more stable than a child's visual system. While it can still develop and improve, there is not much concern with impairing an adult's development. We are more concerned with how well the adult visual system responds to different degrees of stress. Most people have a pretty flexible visual system that can tolerate a moderate degree of 3D technology, allowing them to enjoy a 3D movie, game or show for a short amount of time. However not everyone can. Many people may have underlying visual problems. These visual problems might not allow them to see 3D or might cause symptoms, which can simply be alleviated by stopping the 3D viewing.
You can also try the 20/20/20 rule. Every 20 minutes take off the glasses and look at something 20 feet away for 20 seconds. This will give your eyes a quick break. If a viewer experiences these symptoms, they should get a comprehensive eye exam to see if there is an underlying problem that is causing the strain of the focusing and visual coordination that the 3D requires.
GO: If the inability to see 3D images can help identify vision problems early in life, do we have the medical infrastructure to support a sudden escalation in diagnostic cases as devices like the 3DS popularize and make the technology portable?
NBW: I believe we do have the infrastructure. A lot of these symptoms, if caught in early childhood can be treated much easier and quicker than if they were detected later in life, when treatment would be more complicated or perhaps not applied at all. In a lot of cases if a child is diagnosed with a certain visual disorder at the age of six, it is much easier to treat than at the age of 12, which requires a much more significant intervention.
In terms of sheer numbers, there are enough children vision specialists to adequately handle the types of problems that are being under-treated. Additionally every optometrist graduates with basic training to treat these vision problems. Therefore should there be a rise in the need for this service due to an increase in diagnoses, optometrists certainly would be able to meet that need.
GO: Thanks Dr. Bonilla-Warford!