Virtual reality. Customer sitting in a virtual reality flight simulator. Virtual reality is a means of interfacing with a computer without using a keyboard and conventional screen. A stereo pair of images generated by the computer is displayed inside the helmet. The displayed image changes in direct response to head movement, so the user feels enclosed in a 'virtual' space. Here, the user inputs are made by a joystick on the side of the machine. Although popularly known through such arcade computer games, virtual reality technology is also being applied to spaceflight and medical training and building simulations. Photographed in Chicago, USA.