Medically known as a vestibular balance disorder, motion sickness is a normal response to an abnormal situation. If exposed to enough motion, anyone is susceptible in certain situations. Motion sickness has ruined vacations, by limiting activities, and even incapacitating those affected.
Our balance or equilibrium, and orientation to the space around us is gauged by three sensory systems: The eye (visual) system The balance (vestibular) system of the inner ear The general sensory system including motion, pressure, and position (proprioception) sensors in muscles, joints, and the skin Constantly feeding information to our brainstem and the brain about our present position relating to gravity, these three systems send data for the brain to process, which makes minute adjustments of the head, eyes, body, and joints. When the brain and all three sensory systems are operating properly, our balance system is good. But, when at least one of these sensory systems is not functioning properly, a balance disorder is likely.
The visual system can be affected by motion sickness when improper communication results between the eyes (visual system), and the inner ear (vestibular) system). The inner ears (vestibular system) will tell the brain that there is motion, while the eyes (visual system) does not see this motion, like in an enclosed cabin or passenger compartment, resulting in motion sickness.
The vestibular system (inner ear) deals with balance and position. Working like a carpenter's level, it senses how level we are, and measures rotational and linear movement in our bodies. Many physical disorders can stop this system from working properly, such as ear infections, for example.
The general sensory system has pressure, positions, and motion sensors in our joints, muscles, and skin. Balance problems can result also from the general sensory system not working properly.
The brain uses all the data that these three sensory systems provide together to achieve balance and proper functioning of the central nervous system in response to the data.
Motion sickness usually results in miscommunication between the vestibular (inner ear) sensory system and the visual (eye) sensory system. The eyes might not see motion, but the inner ear sensory system feels the motion, and the resulting differences in data provided to the brain results in motion sickness. A panoramic motion picture or simulator might provide the reverse effect, because the visual (eye) sensory system sees motion but the vestibular (inner ear) sensory system does not feel motion. The body can adapt to the continuous motion after a passage of time, but sometimes that sense of motion will continue after returning to a stable environment, which is called mal de debarquement syndrome.