Kinetosis, or motion sickness, is caused when there is a disconnect between our visual system and vestibular system. It's when our eyes detect movement that is not sensed by our inner ear. The conflict makes our brain think we have been poisoned and begins sending signals to our body to flush a none existent toxin. The result will vary according to user sensitivity, but it often causes discomfort, nausea, profuse sweating, dizziness, headaches, vertigo, excessive salivating, or all of these things. Since the late 1950s, the digital version of motion sickness, simulation sickness, has been greatly researched and documented by the US Military in relation to the development of training simulators. Today, these same factors are true for many computer game players with the effects seemingly magnified by VR experiences.
Motion sickness is caused by a disconnect between two physically moving objects; think of a passenger on a boat. Simulation sickness is caused by the perceived disconnect between a user and the digital environment.
Anyone can develop simulation sickness and since we have yet to have a definitive technical solution, it is the developer's responsibility to manage and mitigate the issue. The following sub sections present six techniques for reducing the effects of simulation sickness.