Editing Motion sickness (section)

===Motion seen but not felt===
In these cases, motion is detected by the [[visual system]] and hence the motion is seen, but no motion or little motion is sensed by the [[vestibular system]]. Motion sickness arising from such situations has been referred to as "visually induced motion sickness" (VIMS).<ref name="So and Ujike 2010" />

====Space motion sickness====
{{Main|Space adaptation syndrome}}
Zero gravity interferes with the vestibular system's gravity-dependent operations, so that the two systems, vestibular and visual, no longer provide a unified and coherent sensory representation. This causes unpleasant disorientation sensations often quite distinct from terrestrial motion sickness, but with similar symptoms. The symptoms may be more intense because a condition caused by prolonged weightlessness is usually quite unfamiliar.{{citation needed|date=July 2021}}

Space motion sickness was effectively unknown during the earliest spaceflights because the very cramped conditions of the spacecraft allowed for only minimal bodily motion, especially head motion. Space motion sickness seems to be aggravated by being able to freely move around, and so is more common in larger spacecraft.<ref name="Benson 2002" /> Around 60% of [[Space Shuttle]] astronauts experienced it on their first flight; the first case of space motion sickness is now thought to be the Soviet [[cosmonaut]] [[Gherman Titov]], in August 1961 onboard ''[[Vostok 2]]'', who reported dizziness, nausea, and vomiting. The first severe cases were in early Apollo flights; [[Frank Borman]] on ''[[Apollo 8]]'' and [[Rusty Schweickart]] on ''[[Apollo 9]]''. Both experienced identifiable and quite unpleasant symptoms—in the latter case causing the mission plan to be modified.{{citation needed|date=July 2021}}

====Screen images====
This type of terrestrial motion sickness is particularly prevalent when susceptible people are watching films presented on very large screens such as [[IMAX]], but may also occur in regular format theaters or even when watching TV or playing games.  For the sake of novelty, IMAX and other panoramic type theaters often show dramatic motions such as flying over a landscape or riding a [[roller coaster]].

In regular-format theaters, an example of a movie that caused motion sickness in many people is ''[[The Blair Witch Project]]''.  Theaters warned patrons of its possible nauseating effects, cautioning pregnant women in particular.  ''Blair Witch'' was filmed with a handheld [[camcorder]], which was subjected to considerably more motion than the average movie camera,<ref name="Wax" /> and lacks the stabilization mechanisms of [[steadicam]]s.

Home movies, often filmed with a cell phone camera, also tend to cause motion sickness in those who view them.  The person holding the cell phone or other camera usually is unaware of this as the recording is being made since the sense of motion seems to match the motion seen through the camera's viewfinder.  Those who view the film afterward only see the movement, which may be considerable, without any sense of motion.  Using the zoom function seems to contribute to motion sickness as well since zooming is not a normal function of the eye.  The use of a tripod or a camera or cell phone with [[image stabilization]] while filming can reduce this effect.{{nosource|date=August 2017}}

====Virtual reality====
{{See also|Virtual reality sickness}}
Motion sickness due to [[virtual reality]] is very similar to simulation sickness and motion sickness due to films.<ref name="ARVI"/>  In virtual reality the effect is made more acute as all external reference points are blocked from vision, the simulated images are [[Stereoscopy|three-dimensional]] and in some cases stereo sound that may also give a sense of motion. The NADS-1, a simulator located at the [[National Advanced Driving Simulator]], is capable of accurately stimulating the vestibular system with a 360-degree horizontal field of view and 13 degrees of freedom motion base.<ref name="NADS"/> Studies have shown that exposure to rotational motions in a virtual environment can cause significant increases in nausea and other symptoms of motion sickness.<ref name="SoLo1999"/>

In a study conducted by the U.S. Army Research Institute for the Behavioral and Social Sciences in a report published May 1995 titled "Technical Report 1027 – Simulator Sickness in Virtual Environments", out of 742 pilot exposures from 11 military flight simulators, "approximately half of the pilots (334) reported post-effects of some kind: 250 (34%) reported that symptoms dissipated in less than one hour, 44 (6%) reported that symptoms lasted longer than four hours, and 28 (4%) reported that symptoms lasted longer than six hours. There were also four (1%) reported cases of spontaneously occurring flashbacks."<ref name="cyberedge" />