A variety of terms are used to refer to symptoms throughout various motion and VR sickness studies. The most common are (based on [143,145,169,171,305]):
After reading this daunting list, it is important to associate it with worst-case analysis. These are the symptoms reported by at least some people for some VR experiences. The goal is to make VR systems and experiences that eliminate these symptoms for as many people as possible. Furthermore, most symptoms may be greatly reduced through repeated exposure and adaptation.
- Nausea: In mild form, users may start having unpleasant sensations associated with the stomach, upper abdomen, esophagus, or throat. As the intensity increases, it gradually leads to the feeling of needing to vomit. This is the most negative and intimidating symptom of VR sickness.
- Dizziness: Users may feel a sensation of movement, such as spinning, tumbling, or swaying, even after the stimulus is removed. This may also include vertigo, which is similar and often associated with malfunctioning vestibular organs.
- Drowsiness: Users may become less alert, yawn, and eventually start to fall asleep.
- Increased salivation: The amount of saliva in the mouth increases, causing more swallowing that usual.
- Cold sweating: Users begin to sweat or increase their sweat, but not in response to increased ambient temperature.
- Pallor: Users experience a whitening or loss or normal skin color in the face, and possibly ears, neck, and chest.
- Warmth/flushing: This corresponds to a sudden increase in perceived warmth, similar to a wave of fever.
- Headache: Users develop headaches that may gradually increase in intensity and remain long after use.
- Fatigue: Users may become tired or exhausted after a long experience.
- Eyestrain: Users may feel that their eyes are tired, fatigued, sore, or aching.
- Accommodation issues: Users may have blurred vision or have difficulty focusing.
Steven M LaValle