Monocularly programmed human saccades during vergence changes?

1 When binocular fixation is shifted to a new target located at a different distance and in a different direction from initial fixation, a binocularly unbalanced saccade occurs at or near the onset of the composite eye movement. Those saccades typically produce good post‐saccadic foveation of the target by one eye or the other. 2 Following such saccades, the better‐aligned eye is typically as well aimed at the target as after pure versional saccades, but the partner eye deviates much more, thus requiring asymmetrical post‐saccadic vergence movement. 3 This phenomenon suggests that during binocular viewing, the retinal eccentricity of a new‐target's image from one of the eyes can be used to programme that eye's own saccade, so that it arrives reliably on target; and that the images of that target from both eyes participate in generating the saccadic excursion of the partner eye. 4 The ecologically useful result is rapid achievement of a high‐resolution monocular view of the new target, although full binocular foveation is achieved much later.