Immersion in virtual environments could adversely effect peoples’ coordination abilities in the real world, according to research at two US universities. In an article in The New Scientist, Jannick Rolland from the University of Central Florida in Orlando and Frank Biocca of Michigan State University say they found in a series of experiments that although subjects were able to adapt quickly to the artificial environments, it took about half an hour for them to re-adjust to the real world. The brain judges distance by the difference in perspective provided by each eye. But the images that are fed into each screen of a virtual reality helmet rarely deliver the same perspective shift as the user’s eyes would, so the brain makes adjustments and has difficulty reverting back to a normal state. The effect is that users will then misjudge distances once the helmets are removed. Rolland suggests that a way around the problem would be to use image- splitting mirrors and overlay computer-generated images onto real world images.