Thanks to the recent advanced screenings of some fifteen minutes of director James Cameron’s highly anticipated release of Avatar in stereoscopic 3D, the movie world is buzzing in chat rooms all across the Internet about the event and about 3D in general. This makes a new report from the Gerson Lehrman Group all the more timely. Their report outlines the very real physiological challenges caused to the human eye and brain by stereoscopic 3D, challenges that must be understood by manufacturers, moviemakers, exhibitors and movie viewers alike.