[How acrophobia impairs visual exploration and gait].

The life-time prevalence of visual height intolerance is 28 % in the general population. More than 50 % of those affected suffer from an impairment of daily behavior and quality of life when confronted with heights. Simultaneous measurements of spontaneous eye and head movements of these subjects while looking from a balcony revealed that visual exploration of the surroundings was restricted compared to that of control subjects. Spontaneous head movements were severely diminished and saccadic eye movements were reduced. Gaze in space was preferably directed towards structures on the horizon. Those susceptible to visual height intolerance exhibited a cautious slowing of gait with small and precarious steps. Restriction of visual exploration during locomotion in a complex terrain may result in falls because obstacles can be overlooked.