Sickness reduction strategies

Through experimental studies that determine VR sickness frequencies and intensities across users, engineers and developers can iterate and produce more comfortable VR experiences. Improvements are needed at all levels. Recall the challenge of the perception of stationarity. Most of the real world is perceived as stationary, and it should be the same way for virtual worlds. Improvements in visual displays, rendering, and tracking should help reduce sickness by ever improving the perception of stationarity. Optical distortions, aliasing, latencies, and other artifacts should be reduced or eliminated. When they cannot be eliminated, then comfortable tradeoffs should be found. New display technologies should also be pursued that reduce vergence-accommodation mismatch, which causes substantial discomfort when close objects appear on a headset that uses a traditional screen and lens combination (recall from Section 5.4).

Even for an ideally functioning headset, locomotion can cause sickness because of vection. Following the strategies suggested in Section 10.2 should reduce the sickness symptoms. A better idea is to design VR experiences that require little or no locomotion.

As last resorts, two other strategies may help to alleviate VR sickness [147]. The first is to regularly practice, which causes adaptation. The amount of fatigue from forced fusion should be expected to decrease as the body becomes adjusted to the unusual combination of stimuli. Of course, if the VR experience makes most people sick, then asking them to ``power through'' it a dozen times or more may be a bad idea. Finally, users could take drugs that reduce susceptibility, much in the way that some people take air sickness pills before boarding a plane. These pills are usually antihistamines or anticholinergics, which have unfortunate side effects such as fatigue, drowsiness, impaired cognitive performance, and potential for addiction in some cases.