[As opposed to normal subjects, eyelid position doesn't interfere with postural behavior in blind subjects].
OBJECTIVE
A previous study has shown some behavioral differences in normal subjects depending on the position of the eyelids: the postural behavior was varying if the subject had the eyes open in darkness or the eyes closed. In this study, we explore the possible role of vision on this behavior.


METHODS
The postural behavior of 12 blind and nine visually impaired participants was studied during undisturbed upright stance.


RESULTS
In this sample, no difference was found in the conditions eyes open in the dark and eyes closed: the observed behavior in blind and visually impaired subjects is different compared to normal sighted subjects who show a visual preference even in total darkness when the eyes are open. Our two groups (blind and visually impaired) actually show a difference on the median frequency of the centre of gravity displacements.


CONCLUSIONS
Our results suggest an adaptive mechanism of the central nervous system in healthy individuals to predominantly weigh visual cues when the eyelids remain open. Good visual acuity and time seem to be necessary for this process.
Olin
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C
EA4338, laboratoire de physiologie de l'exercice, université de Savoie, domaine scientifique de Savoie-Technolac, 73376 Le-Bourget-du-Lac cedex, France.
Rougier
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P
D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D001766:Blindness / Q000503:physiopathology*; D003624:Darkness; D005143:Eyelids / Q000502:physiology*; D005260:Female; D006112:Gravitation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement; D004856:Postural Balance / Q000502:physiology*; D011187:Posture; D011434:Proprioception / Q000502:physiology; D014786:Vision Disorders / Q000503:physiopathology