No, it's not just you. According to studies recently conducted by the University of California, Berkeley, the viewing of stereoscopic 3D displays does indeed cause visual discomfort, fatigue and headaches. The problem appears to come from the fact that the viewers' eyes are simultaneously trying to focus on the screen, and on objects that appear to be located either in front of or behind that screen.

The studies involved 24 adult subjects, who viewed 3D content both on small, consumer electronics-style screens, and on larger, theater-style screens. With the smaller screens, which are viewed at a closer distance, content that appeared to be located in front of the screen caused the most discomfort. Interestingly, however, viewing of the larger, more distant screens was most uncomfortable when content appeared to be located behind the screen.

"When watching stereo 3D displays, the eyes must focus - that is, accommodate - to the distance of the screen because that's where the light comes from," said Martin S. Banks, professor of optometry and vision science. "At the same time, the eyes must converge to the distance of the stereo content, which may be in front of or behind the screen."

In further studies, the team suggests that a larger number of test subjects be used, including children. The U Berkeley researchers hope that their findings could be used to establish guidelines for the positioning of viewers relative to 3D displays.

"Discomfort associated with viewing Stereo 3D is a major problem that may limit the use of technology," said Banks. "We hope that our findings will inspire more research in this area."

The research was recently published in The Association for Research and Vision in Ophthalmology's Journal of Vision.