Horopter Animation

Above is a simulation of the changes in the retinal location of a dot as it moves in relation to the horopter.

Notice two sets of changes in the pattern of red dots under the eyes:

• The change in location across the retinas as the dot sweeps back and forth while it is beyond the horopter. The values of the red dots change indicating that the image is changing location on the retina. But the angular disparity pattern (across I and K) remains relatively constant indicating that the dot is not getting closer or farther.
• The change in location across the retina as the dot moves to the horopter (the number 4). Notice that the relationship between I and K changes. This indicates that the dot now occupies a different distance from us.