Women are more likely to experience virtual reality (VR) sickness than men, which could pose a major challenge to the mass market success of VR. Because VR sickness often results from a visual-vestibular conflict, an effective strategy to mitigate conflict is to restrict the user’s field-of-view (FOV) during locomotion. Sex differences in spatial cognition have been well researched, with several studies reporting that men exhibit better spatial navigation performance in desktop three-dimensional environments than women. However, additional research suggests that this sex difference can be mitigated by providing a larger FOV as this increases the availability of landmarks, which women tend to rely on more than men. Though FOV restriction is already a widely used strategy for VR headsets to minimize VR sickness, it is currently not well understood if it impedes spatial learning in women due to decreased availability of landmarks. Our study (n=28, 14 men and 14 women) found that a dynamic FOV restrictor was equally effective in reducing VR sickness in both sexes, and no sex differences in VR sickness incidence were found. Our study did find a sex difference in spatial learning ability, but an FOV restrictor did not impede spatial learning in either sex.

Virtual reality sickness typically results from visual-vestibular conflict. Because self-motion from optical flow is driven most strongly by motion at the periphery of the retina, reducing the user’s field-of-view (FOV) during locomotion has proven to be an effective strategy to minimize visual vestibular conflict and VR sickness. Current FOV restrictor implementations reduce the user’s FOV by rendering a restrictor whose center is fixed at the center of the head mounted display (HMD), which is effective when the user’s eye gaze is aligned with head gaze. However, during eccentric eye gaze, users may look at the FOV restrictor itself, exposing them to peripheral optical flow which could lead to increased VR sickness. To address these limitations, we develop a foveated FOV restrictor and we explore the effect of dynamically moving the center of the FOV restrictor according to the user’s eye gaze position. We conducted a user study (n=22) where each participant uses a foveated FOV restrictor and a head-fixed FOV restrictor while navigating a virtual environment. We found no statistically significant difference in VR sickness measures or noticeability between both restrictors. However, there was a significant difference in eye gaze behavior, as measured by eye gaze dispersion, with the foveated FOV restrictor allowing participants to have a wider visual scan area compared to the head-fixed FOV restrictor, which confined their eye gaze to the center of the FOV.

Virtual reality (VR) has enjoyed significant popularity in recent years. Where navigation has been a fundamental appeal of 3D applications for decades, facilitating this in VR has been quite a challenge. Over the past decades, various virtual locomotion techniques (VLTs) have been developed that aim to offer natural, usable and efficient ways of navigating VR without inducing VR sickness. Several studies of these techniques have been conducted in order to evaluate their performance in various study conditions and virtual contexts. Taxonomies have also been proposed to either place similar techniques in meaningful categories or decompose them to their underlying design components. In this survey, we aim to aggregate and understand the current state of the art of VR locomotion research and discuss the design implications of VLTs in terms of strengths, weaknesses and applicability.

Recent studies show that women are more susceptible to visually-induced VR sickness, which might explain the low adoption rate of VR technology among women. Reducing field-of-view (FOV) during locomotion is already a widely used strategy to reduce VR sickness as it blocks peripheral optical flow perception and mitigates visual/vestibular conflict. Prior studies show that men are more adept at 3D spatial navigation than women, though this sex bias can be minimized by providing women with a larger FOV. Our study provides insight into the relationship between sex and FOV restriction with respect to VR sickness and spatial navigation performance which seem to conflict. We find the use of an FOV restrictor to be effective in mitigating VR sickness in both sexes while we did not find a negative effect of FOV restriction on spatial navigation performance.

During terrestrial activities, sensation of pressure on the skin and tension in muscles and joints provides information about how the body is oriented relative to gravity and how the body is moving relative to the surrounding environment. In contrast, in aquatic environments when suspended in a state of neutral buoyancy, the weight of the body and limbs is offloaded, rendering these cues uninformative. It is not yet known how this altered sensory environment impacts virtual reality experiences. To investigate this question, we converted a full-face SCUBA mask into an underwater head-mounted display and developed software to simulate jetpack locomotion outside the International Space Station. Our goal was to emulate conditions experienced by astronauts during training at NASA's Neutral Buoyancy Lab. A user study was conducted to evaluate both sickness and presence when using virtual reality in this altered sensory environment. We observed an increase in nausea related symptoms underwater, but we cannot conclude that this is due to VR use. Other measures of sickness and presence underwater were comparable to measures taken above water. We conclude with suggestions for improved underwater VR systems and improved methods for evaluation of these systems based on our experience.