The American Optometrist Association (AOA) says there's no need to worry about children playing the new 3D version of Nintendo's DS console. But Nintendo is sticking by its warnings that very young children should steer clear.

Yes, you did read that right. Medical experts say it's okay to use the device, while Nintendo says it could be dangerous.

As we noted last week, Nintendo officially warned that children aged under six should not use the 3DS, and suggested the device might damage the development of their vision.

Now the AOA is reported to have said that the device should be safe for most children under 6, and that in some cases "3D viewing may actually help uncover subtle disorders that, left uncorrected, often result in learning difficulties." (Source: gamespot.com)

Ridges the Key to 3D Perception

The logic behind that claim lies in the way the device works.

The console doesn't, as you might expect, use its two separate screens to create the 3D effect: only the top screen has a 3D display. It contains a special overlay with ridges below the surface. These ridges mean certain parts of the screen can only be seen from restricted angles -- in other words each eye can only see half of the screen.

This allows each eye to see a separate image, which contains a slightly different perspective than the other: the brain's attempts to cope with this disparity causes an illusion of depth. The effect only works to its potential when viewers look from a particular angle, which is why it is so well suited to a small console.

The AOA logic is that children with specific visual difficulties that aren't a noticeable problem in everyday life may experience discomfort or be unable to appreciate the 3D effect, thus exposing the issue. However, it stressed that parents should still rely on regular eye exams rather than use 3D effects as their only way to check up on vision.

Nintendo Prepared to Take Sales Hit

For its part, Nintendo maintains its position. President Satoru Iwata said it was right to make the warning, even though it may well harm sales. He said that the threat of lawsuits was one of the reasons the company issued the safety advice, but that it wasn't the main factor behind it.

In a surprisingly frank admission, Iwata also noted his concern that some parents treat video games as a form of babysitter. (Source: wsj.com)