SAN JOSE, Calif. Experts in human perception are expressing concerns stereo 3-D TVs now hitting the market could cause eye strain and related health problems. Industry groups are actively discussing the topic, but in their rush to get systems out the door vendors have yet to fund any major studies of the issues.
Stereo 3-D movies and television could generate as many as seven different perceptual problems, said Martin Banks, a professor of optometry and vision science at the University of California at Berkeley. He gave a talk earlier this month for a broad group of consumer and Hollywood technologists about some of his biggest concerns, and was invited to come back to give a day-long course.
"They seem concerned about it, and my impression is they want to address this," Banks said of multiple contacts he has had with the industry. "They know they will kill the business if they make an unpleasant experience for people, [but] the question is what they will implement," he added.
"I think there are real things to be concerned about with the use of stereo displays becoming very widespread, especially if younger children are exposed to them routinely," added Simon Watt, a lecturer in the school of psychology at Bangor University in Wales who, like Banks, has been conducting studies on eye movements and stereo 3-D displays.
One of the main issues the researchers are studying is the so-called convergence-accommodation conflict. People watching stereo 3-D content have to adjust what they see at one point on a flat screen to information in the content that tells them that object is at another point in 3-D space. Such adjustments are not needed in the real world, so the human brain is not wired to handle them smoothly.
"We were the first to show that causes a variety of symptoms people can find unpleasant" such as headache and fatigue, said Banks.
Recent 3-D movies such as "Avatar" did a good job of minimize the effect, Banks said. But "as you decrease the distance [to the display] the problems created by this conflict accelerate and it's non-linear so they accelerate quickly.
"Things you could get away with in movies, you can't in a video game where a kid is close to the screen, so I am more troubled about stereo 3-D TVs than movies," he added.
Both Banks and Watt are working on one possible solution. In separate efforts they are developing so-called multi-focal-plane displays that could reduce eye strain.