Definition of binocular disparity (far and near). The full black circle is the point of fixation. The blue object lies nearer to the observer. Therefore it has a "near" disparity dn. Objects lying more far away (green) correspondingly have a "far" disparity df. Binocular disparity is the angle between two lines of projection in one eye. One of which is the real projection from the object to the actual point of projection. The other one is the imaginary projection running through the focal point of the lens of the one eye to the point corresponding to the actual point of projection in the other eye. For simplicity reasons here both objects lie on the line of fixation for one eye such that the imaginary projection ends directly on the fovea of the other eye, but in general the fovea acts at most as a reference. Note that far disparities are smaller than near disparities for objects having the same distance from the fixation point.
{{Information |Description=Definition of binocular disparity (far and near). The full black circle is the point of fixation. The blue object lies nearer to the observer. Therefore it has a "near" disparity d<sub>n</sub>. Objects lying more far away (green