Bruce Bridgeman, a psychology professor at the University of California, Santa Cruz, couldn't see in three dimensions for most of his life. That was until he went to a 3-D showing of the movie Hugo and, amazingly, had his depth perception restored, according to a story first reported by the BBC and later picked up by CNN.
Great! Get everyone with vision problems in line to see the new Transformers!
Well, not quite. 3-D movies aren't going to be the next panacea for the visually impaired (although at least you won't have to sit through Transformers?). But, under the right circumstances, strapping on the plastic glasses and picking at some popcorn could help.
Stereoblindness--the inability to see more than two dimensions--can be caused by strabismus, a condition where the eyes are misaligned. The brain often adapts to strabismus by disregarding the input from one eye and taking all of the information from the other. But the feed from both eyes is what allows most people to see in three dimensions, so limiting the brain to one causes stereoblindness. The brain's an amazing organ, though: plasticity--the brain's ability to disregard tasks it isn't employing and also pick up on tasks it hasn't been using--can help repair stereovision.
The classic example of this is the eyepatch treatment for what's commonly known as lazy eye, where one eye points in a different direction than the "good" eye, causing stereoblindness. By placing the patch over the good eye, the brain learns to work with what it has, repairing neuronal connections so the lazy eye does its job. When the patch comes off, stereovision can be restored. Recent research has shown it's possible to pull this trick off using a game of Tetris, too.