Editing Saccade (section)

==In depth==
When exploring the visual environment with the gaze, humans make two to three fixations a second. Each fixation involves binocularly coordinated movements of the eyes to acquire the new target in three dimensions: horizontal and vertical, but also in-depth. In literature it has been shown how an upward or a vertical saccade is generally accompanied by a divergence of the eyes, while a downward saccade is accompanied by a convergence.<ref>{{Cite journal|last=J.T. Enright|date=1984|title=Changes in vergence mediated by saccades|journal=The Journal of Physiology|volume=350|pages=9–31|pmid=6747862|pmc=1199254|doi=10.1113/jphysiol.1984.sp015186}}</ref> The amount of this ''intra-saccadic'' ''vergence'' has a strong functional significance for the effectiveness of binocular vision.<ref>{{Cite journal|last=Gibaldi Agostino, Martin S. Banks|date=2019|title=Binocular Eye Movements are Adapted to the Natural Environment|journal=Journal of Neuroscience|volume=39|issue=15|pages=2877–2888|doi=10.1523/JNEUROSCI.2591-18.2018|pmid=30733219|pmc=6462454}}</ref> When making an upward saccade, the eyes diverged to be aligned with the most probable uncrossed disparity in that part of the visual field. On the other way around, when making a downward saccade, the eyes converged to enable alignment with crossed disparity in that part of the field. The phenomenon can be interpreted as an adaptation of rapid binocular eye movements to the statistics of the 3D environment, in order to minimize the need for corrective vergence movements at the end of saccades.