Abstract
Abstract: :
Purpose: To report the contribution of the retinal micromovements (microsaccades and drifts) in the maintenance of steady binocular fixation in normal test persons. Methods: Start and end microsaccadic distance, as well as start and end drift distance to the center of fixation, were quantified binocularly in 10 normal test persons during a 40 second fixation task, using an infrared recording technique. Results: The mean post microsaccadic distance to the center of fixation was 0.46 degrees (range 0.21–0.91 degrees) with only 33.2% of the microsaccades corrective. The mean post drift distance to the center of fixation was 0.41 degrees (range 0.22–0.72 degrees) with 52.2% of the drifts corrective. A significant positive correlation between the post saccadic distance to the fixation centre and the fixation area, as well as significant positive correlation between post drift distance and the fixation area could be found (p<0.005, r=0.65 for both correlations). Conclusions: Microsaccades contributes only in a smaller degree to the maintenance of binocular fixation, whereas the eye movements during drifts (slow control) keeps the eye in place.
Keywords: eye movements • eye movements: saccades and pursuits • eye movements: recording techniques