Effects of Vision on Postural Control in Neurologically Healthy Individuals

The purpose of this chapter is to characterize how the postural system of healthy individuals is capable of adaption when facing distinct levels of challenge, all planned to vary the visual context involved. A series of postural studies showed a variety of circumstances in which the postural control system faced both stronger, mechanical and subtle, sensorial perturbations. Effects of vision were tested in tasks such as moving line-of-gaze in space (during saccadic and smooth pursuit eye movements), grasping an object (under different optic flow conditions), three-ball juggling (under narrow and wide stances), performing a ballet skill (with eyes opened and blindfolded), and driving a car (under simulated conditions); additionally, effects of aging on posture are discussed. In summary, the authors suggest that studies on posture and vision must consider both multiple levels of the visual system functioning (eyes, head, trunk, and whole-body movements) and lifespan postural changes in order to advance our knowledge of the process of acquisition and use of visual information to stabilize posture.