We react like that, experts say, because our brains are easily fooled when what we see on a display tracks our head movements. “We have a reptilian instinct that responds as if it’s real: Don’t step off that cliff; this battle is scary,” Jeremy Bailenson, the founding director of Stanford’s Virtual Human Interaction Lab, told me. “The brain hasn’t evolved to tell you it’s not real.”

Much of the excitement about virtual reality has come from the gaming community. Who wouldn’t want to experience a game so completely? But gaming is just the start. At Sony, Marks has worked with NASA to conjure the experience of standing on Mars—a view that could help scientists better understand the planet. David Laidlaw, the head of the Visualization Research Lab at Brown University, told me that his team has re-created a temple site in Petra, Jordan, enabling researchers to see previously unclear relationships between objects found there.

Google is testing Expeditions, a way of sending students to places like the Great Barrier Reef, where they can virtually scuba dive as part of a lesson on marine biology and ocean acidification. Similar approaches may enhance professional training. By donning a pair of goggles, a neurosurgeon could navigate brain structures before surgery; a chemist could step inside a drug to understand it on the cellular level; an architect could walk through a building she’s designing.

Another possibility: Imagine that you’re unable to attend a family gathering. With a pair of glasses, you’re in the middle of the action. And everyone there wears glasses that make it appear as though you’re present. The whole thing is recorded, so you can replay the experience whenever you’d like. Ten years from now, such a scenario might be common.

And consider the potential for telecommuting. Henry Fuchs, a professor at the University of North Carolina at Chapel Hill and a leader in the field, envisions virtual offices. You could use the physical space of your house—a real desk, a real computer—but interact with your colleagues as if they were in the same room as you.

Seeing Through Others’ Eyes

In his lab at Stanford, Bailenson studies how virtual reality changes behavior. He’s found that if your avatar is taller than you are in real life, you become more confident. If you have a particularly attractive avatar, you become friendlier. If you’re young and you have an avatar that is a senior citizen, you save more money. These changes last even after you leave the virtual realm.

And avatars could soon become more convincing. Most commercial virtual-reality systems capture only the movement of your head and hands. In 2013, though, Apple acquired PrimeSense, an Israeli company developing technology to track the movements of your whole body with infrared sensors and special microchips. And a company called Faceshift is working to capture facial expressions, so that if you smile or roll your eyes, your avatar will too.