Trees once looked like green panels for Bruce Bridgeman. He'd have to move his head to gauge the relative closeness of objects.
For most of his life, he had poor depth perception. His eyes pointed outward and did not allow him to see, in stereo, a single image with both eyes.
But in February 2012, something changed when he went to a movie theater with his wife. He put on a pair of 3-D glasses to watch the film "Hugo" and, to his amazement, the characters and scenery in this film jumped out at him in greater stereo vision than he had experienced before.
What's more, after returning the glasses and leaving the theater, Bridgeman's perception of the real world was enhanced as well. A lamppost jumped out from the background, and the trees, cars and people looked somehow more vivid. This was the world with depth. Bridgeman was "euphoric."
"Suddenly, things began to jump out at me," said Bridgeman, a professor of psychology at the University of California, Santa Cruz.
The effect has stuck around since he saw the movie 16 months ago.
It's impossible to prove scientifically that the film itself altered his visual system, but his hope is that his story could help others with similar eye conditions who struggle through months of training to attempt to see more vividly.
Other experts say the vivid 3-D movie could have indeed jolted Bridgeman's visual system in this way, but that it wouldn't work as a quick fix for most people with eye alignment problems. It's possible with Bridgeman's unique set of circumstances, it was exactly what he needed, but it would probably help few people.
"Certainly immersion in a 3-D movie could, if somebody had a marginal vision system, could absolutely improve it," said Paul Harris, associate professor at the Southern College of Optometry in Memphis, Tennessee, who has not evaluated Bridgeman. But, he adds, "I wouldn't prescribe (a movie)."
In 1983, at the University of California, Berkeley, he collaborated with two colleagues on a study of his own vision.
Through such testing, it was obvious that his stereo vision wasn't great, and that he had exotropic vision, meaning his eyes pointed in different directions. But he didn't know what perceptual difference it would make to view the world more in stereo, until he saw "Hugo."
Now, objects that appeared to be on top of each other seem more separate, and 2-D movies are recognizably flat -- before, they were perhaps "just as real as the real world," he said.
It is estimated that between 3% and 5% of people are stereo-blind or have large deficits in stereo vision.
Researchers have suggested that creating video games with three-dimensional information could be used to help children and adults with eye misalignment problems achieve improved stereo vision.