Auditory biofeedback to control vertical and horizontal eye movements in the dark

Area of Science:

• Ophthalmology
• Neuroscience
• Bioengineering

Background:

• Oculomotor control in darkness is crucial for visual stability.
• Previous research focused on horizontal gaze control with auditory biofeedback.
• Vertical gaze control in darkness remained largely uninvestigated.

Purpose of the Study:

• To investigate the effect of 2D auditory biofeedback on horizontal and vertical eye movements in total darkness.
• To compare oculomotor behavior in light, darkness, and darkness with biofeedback.

Main Methods:

• Monocular infrared limbal eye tracking was used.
• Three normal subjects participated under three conditions: light, darkness, and darkness with 2D auditory biofeedback.
• Fixational eye movements (horizontal and vertical) were recorded.

Main Results:

• In darkness, eye movements showed significant drifts and saccades (>2 degrees).
• Auditory biofeedback reduced these drifts and saccades to levels similar to light conditions (<0.5 degrees).
• Percent time on target improved from ~50% in darkness to ~80% with biofeedback.

Conclusions:

• Two-dimensional oculomotor auditory biofeedback effectively enhances fixation accuracy in total darkness.
• This biofeedback is sufficient to restore near-normal oculomotor control for both horizontal and vertical eye movements.
• Auditory biofeedback represents a promising tool for improving gaze stability in visually deprived conditions.