Motion sickness (also known as car, sea, train, or air sickness) occurs when the body is subjected to accelerations of movement in different directions or under conditions where visual contact with the actual outside horizon is lost. The brain receives contradictory information from its motion sensors such as the eyes or semicircular canals in the middle ears that provide information about body position. Symptoms include dizziness, fatigue, and nausea, which may progress to vomiting. Prevention is best accomplished by seeking areas of lesser movement in an interior location of a ship or by facing forward and looking outside an airplane. Various prescription and over-the-counter medications are available that may prevent or limit the symptoms of motion sickness.