Value of abnormal retinal correspondence in binocular vision.

ABNORMAL retinal correspondence has been a vexed subject since the physiology of binocular vision and strabismus have been discussed, but it seems to be generally accepted that it is an adaptation of the sensory relations of the retina to the squinting position. Normal retinal correspondence is present when any pair of corresponding points have a common visual direction; abnormal retinal correspondence occurs when retinal areas which are ordinarily disparate prove to have a common visual direction (Swan, 1950). At the onset of a squint, retinal correspondence is normal and projection is incorrect by an amount equal to the angle of deviation, but according to Duke-Elder (1950):