Abstract: In order to evaluate the regulating function of the central nervous system after being exposed to an environment of sensory conflict, 10 healthy young men experienced the reversed vision tests during walk wearing vertically and horizontally reversed vision prisms, and dynamic equilibrium tests were conducted before and after the reversd vision tests separately on different days with intervals of 5～7d. The reversed vision could cause disorientation and motion sickness symptoms obviously, and lead to a decrease of equilibrium function. But the decrease and expression of equilibrium function are different in subjects with different serious symptoms. There is a slight delay for equilibrium reaction in the subjects who have slight symptoms. There are decrease for equilibrium ability, and change for equilibrium strategy and sensory organ effects besides delay for equilibrium reaction in the subjects who have serious symptoms. It is thought that the equilibrium tests before and after reversd vision tests could reflect the regulating function of human to dismatching sensory signals and exposelatent unstability on equilibrium function, and this method is useful for evaluating susceptibility of motion sickness.

Key words: reversed vision disorientation, postur e equilibrium, motion sickness