Fixational eye movements and autokinesis in amblyopes

Eye movements were recorded from amblyopic and non-amblyopic eyes during monocular viewing of a small target on either a patterned or a patternless background. A continuous measure of autokinesis was also obtained. The variance in eye position was greater in amblyopic eyes than in non-amblyopic eyes. The presence of a patterned background did not reduce the variance in eye position of amblyopic eyes. Autokinesis was greater in amblyopic eyes, but was not correlated with the eye movements. A patterned background significantly reduced the magnitude of autokinesis in amblyopic eyes. These results provide support for the hypothesis that a patterned background improves the accuracy of visual direction by reducing spurious extraretinal signals.