3-D can have adverse health effects

Chances of a repeat of 1997 event are remote

By ROBYN WEISMAN

Back in 1997, several hundred Japanese schoolchildren suffered seizures watching an episode of "Pokemon" that had brief intervals of flashing lights. The strobing was only a fraction of the 60 Hz refresh rate used in today's 3-D shutter glasses. Still, Japan's NHK won't broadcast in 3-D until it completes a minimum five-year study on whether it could trigger latent adverse health effects.

Tom Randolph, CEO of Kerner Technologies, worries hardcore 3-D gamers might fall prey to seizures and recommends shutter-glasses makers increase their refresh rates to a minimum 120 Hz. But Randolph says if your eyes aren't feeling distress, chances are your brain isn't either. "I think watching 3-D for two hours is safe, even on a red-blue anaglyph. And people who don't feel good are smart enough to walk out."