A virtual touch screen (VTS) is a user interface system that augments virtual objects into reality either through a projector or optical display using sensors to track a person's interaction with the object. For instance, using a display and a rear projector system a person could create images that look three-dimensional and appear to float in midair.[1] Some systems utilize an optical head-mounted display to augment the virtual objects onto the transparent display utilizing sensors to determine visual and physical interactions with the virtual objects projected.[2]