Flight simulators are examples of virtual environment (VE) systems that often give rise to a form of discomfort resembling classical motion sickness. The major difference between simulator sickness and other forms of motion sickness is that the former exhibits more oculomotor-related symptoms and far less actual vomiting. VEs of the future are likely to include more compellingly realistic visual display systems, and these systems can also be expected to produce adverse symptoms. The implications of simulator sickness for future uses of VEs include adverse consequences for users' safety and health, user acceptance, training effectiveness, and overall system performance. Based on data from a factor analysis of over 1000 Navy and Marine Corps pilot simulation exposures, a new scoring procedure for simulator sickness has recently been developed (Lane & Kennedy, 1988; Kennedy, Lane, Berbaum, & Lilienthal, 1992). The factor analytic scoring key provides subscales for oculomotor stress (eyestrain), nausea, and disorientation. Simulators are being examined in terms of these factor profiles to identify causes of simulator sickness. This approach could also be used in evaluating motion sickness-like symptomatology that occurs in connection with the use of VEs. This paper describes the use of the multifactor scoring of the Simulator Sickness Questionnaire (SSQ) in diagnosing sources of simulator sickness in individual simulators. Reanalysis by this new methodology was employed to standardize existing simulator sickness survey data and to determine whether relationships existed that were missed by the more traditional scoring approaches.

Human perceptual systems have evolved to provide accurate information about orientation and movement through the environment. However, these systems have been challenged in the past century by modern transportation devices and will be further challenged by virtual environments (VEs) and teleoperator systems. Illusory self-motion within a VE (“cyberspace”) will be entertaining and instructive, but for many users it will result in motion sickness (“cybersickness”). Sensory conflict theory and the poison hypothesis provide an unproven theoretical foundation for understanding the phenomenon. Although no single engineering solution is likely, the problem can be contained by a combination of engineering design, equipment calibration, and exposure management.

Visually induced motion sickness is a syndrome that occasionally occurs when physically stationary individuals view compelling visual representations of self-motion. It may also occur when detectable lags are present between head movements and recomputation and presentation of the visual display in helmet-mounted displays. The occurrence of this malady is a critical issue for the future development and implementation of virtual environments. Applications of this emerging technology are likely to be compromised to the extent that users experience illness and/or incapacitation. This article presents an overview of what is currently known regarding the relationship between visually specified self-motion in the absence of inertial displacement and resulting illness and perceptual-motor disturbances.

The widespread diffusion of immersive virtual environments (VE) is threatened by persistent reports that some users experience simulation sickness, a form of motion sickness that accompanies extended use of the medium. Experience with the problem of simulation sickness is most extensive in the military where the illness has accompanied the use of various simulators since the 1950s. This article considers the obstacles presented by simulation sickness to the diffusion of VE systems, its physiological and technological causes, and, finally, the remedies that have been suggested to fix the problems. This issue is also considered in light of previous reports of purported illnesses that accompanied the diffusion of other communication technologies.

Researchers in the field of virtual environments (VE), or virtual reality, surround a participant with synthetic stimuli, The flight simulator community, primarily in the U.S. military, has a great deal of experience with aircraft simulations, and VE researchers should be aware of the major results in this field. In this survey of the literature, we have especially focused on military literature that may be hard for traditional academics to locate via the standard journals. One of the authors of this paper is a military helicopter pilot himself, which was quite useful in obtaining access to many of our references. We concentrate on research that produces specific, measured results that apply to VE research. We assume no background other than basic knowledge of computer graphics, and explain simulator terms and concepts as necessary. This paper ends with an annotated bibliography of some harder to find research results in the field of flight simulators: • The effects of display parameters, including field-of-view and scene complexity; • The effect of lag in system response; • The effect of refresh rate in graphics update; • The existing theories on causes of simulator sickness; and • The after-effects of simulator use Many of the results we cite are contradictory. Our global observation is that with flight simulator research, like most human-computer interaction research, there are very few “correct” answers. Almost always, the answer to a specific question depends on the task the user was attempting to perform with the simulator.