"Is there a limit on how much a child should be viewing 3-D? Yeah. How much is it? I don't know. Let's use some sound judgment," he said.
Optometrists: Nintendo 3DS could ID vision issues →
Dr. Jim Sheedy, director of the Vision Performance Institute at Pacific University in Forest Grove, Ore., said parents should limit kids' use of the 3DS just as they limit computer or game console use.