"Unlike most contemporary 360-degree visual simulation environments, the virtual environment display system does not make use of large, expensive, special purpose projection configurations; The described system is portable and low-cost without large space and equipment requirements. Unlike other research efforts in head-mounted displays, this system is unique in presenting a stereoscopic image that fills the user's field of view completely and in its configuration with speech and tactile input technology."
Fisher, Scott. "Virtual Interface Environment". California: NASA Ames Research Center, 1988.