Simulator sickness and cybersickness

Once displays are used, the choices discussed in Section 2.1 reappear: They may be fixed screens that surround the user (as in a CAVE VR system) or a head-mounted display that requires tracking. Vehicle simulators are perhaps the first important application of VR, with the most common examples being driving a car and flying an airplane or helicopter. The user may sit on a fixed base, or a motorized based that responds to controls. The latter case provides vestibular stimulation, for which time synchronization of motion and visual information is crucial to minimize sickness. Usually, the entire cockpit is rebuilt in the real world, and the visual stimuli appear at or outside of the windows. The head could be tracked to provide stereopsis and varying viewpoints, but most often this is not done so that comfort is maximized and technological side effects are minimized. The branch of visually induced motion sickness that results from this activity is aptly called simulator sickness, which has been well-studied by the US military.

The term cybersickness [209] was proposed to cover any sickness associated with VR (or virtual environments), which properly includes simulator sickness. Unfortunately, the meaning of the term has expanded in recent times to include sickness associated with spending too much time interacting with smartphones or computers in general. Furthermore, the term cyber has accumulated many odd connotations over the decades. Therefore, we refer to visually induced motion sickness, and any other forms of discomfort that arise from VR, as VR sickness.