Parents have always worried about Junior ruining his eyesight by playing too many video games. But with the advent of virtual reality, those fears may have added justification. A recent study at Waseda University in Tokyo suggests that prolonged exposure to stereoscopic visual effects, typical of virtual reality systems, can temporarily impair the eye's ability to focus on real objects.
Waseda professor and virtual reality expert Kageyu Noro enlisted four student volunteers to watch a video of a can rotating slowly in space, while wearing special goggles to create the 3-D effect. After an hour of viewing, the tape was turned off, and the students were asked to focus on two points in succession--the first one 40 inches away, and the second 10 inches away. It took the students an average of 1.7 seconds to refocus, more than double the usual time, Noro says. Control tests using ordinary, two-dimensional computer screens produced no such aberrations. Although Noro tested goggles with rapidly flickering shutters that allow only one eye to see at a time, he believes the effect would be the same with other varieties of 3-D goggles. Although the students' vision quickly returned to normal, Noro favors guidelines limiting the depth and intensity of 3-D images used in game software.