Control and sense of eye movement behind closed eyelids.

To investigate the question of what happens with regard to position sense and control of the human eyes when the eyelids are closed, the contact-wire-free electromagnetic eye movement recording method was developed. It was shown that after the start of blinking of eyelid closure, the eyeball moves up as the upper eyelids come down. Experimental data show human inability to maintain a given position of the eyes in the head under the closed lids. When the subject was asked to follow a simple geometrical path, a very weak metrical and topological correspondence between desired and actual paths occurred with closed eyes. It is proposed that the poor control of eye movements behind closed eyelids is due to the lack of available information about the eye position in the head. The assumption was confirmed by providing artificial auditory feedback about the eyeball position to the subject, which can be effectively used for gaze stabilization by the subject. It is suggested that visual information is the only useful basis for eye movement regulation under normal conditions.