for some, 3d movies a pain in the head - digital projector

Fans and sports fans who hope 3D TV brings the ultimate home theater experience may want to check their eyes first --
Or risk a 3D headache. S.
Eye experts said Saturday.
Three-more and more popular
James Cameron's "Avatar" and other 3-D movies-
Box office revenue now stands at $1 billion.
The 3D TV was unveiled this week at the International Consumer Electronics Show in Las Vegas.
While the new digital 3D technology makes the experience more comfortable for many people, for some with eye problems, long 3D sessions can cause head pain, they say.
Dr. Michael Rosenberg said: "There are a lot of people walking around with very small eye problems, such as slight muscle imbalance, where the brain is naturally processed under normal circumstances, "Professor of Ophthalmology, Northwestern University of Chicago, Fanberg School of Medicine.
In a 3D movie, he says, these people face a whole new sensory experience.
"This means a greater mental effort to make headaches easier," Rosenberg said in a telephone interview . ".
In normal vision, each eye sees things in a slightly different angle.
"When this is processed in the brain, there is a perception of depth," said Dr. Deborah Friedman, professor of ophthalmology and neurology at the University of Rochester Medical Center in New York.
"The fantasy of the three dimensions you see in the movie is not exactly aligned like your eyes and brain.
If your eyes are a bit uncomfortable in the first place, then your brain needs a lot of effort now.
"For some people, this difference can give them a headache," she said . ".
Dr. John Kerry, an eye doctor in Kansas City, Missouri and a researcher at the American Academy of Ophthalmology, said that some people who do not have normal deep perception can't see 3D at all.
He said that people with problems with eye muscles are in trouble when dealing with 3D images because the eyes are not pointing to the same object.
Experts say there is no study on how common headaches are after watching a 3D movie, but Rick Heineman, a spokesman for RealD, a company that provides 3D equipment to cinemas, the main reason 3D technology has never taken off is headache and nausea.
The company supplies 3D equipment to 90% of the U. S.
Cinemas with 3D capabilities have reached agreements with Sony, Panasonic, JVC, Toshiba and direct television, which said, its updated digital technology solves many problems that often cause discomfort for 3D viewers.
The old 3D technology involves using two movie projectors, one to project the left eye image, and one to project the right eye image, says Mr heyniman. Three-
D glasses allow the audience to see different images on each eye.
"People often complain about headaches, really because the projector is not in line," heyniman said . ".
Heineman's company uses a digital projector that switches 144 times per second between the left and right eye images to help overcome some of the old problems.
"By using a digital projector, these problems have been solved," he said . ".
Friedman says she thinks most people will do a good job in 3D movies and 3D TV, but Rosenberg says people may soon get tired of this novelty.
"I think it will be a gimmick.
"I suspect there will be a lot of people saying it's a little neat but not comfortable," he said . ".