Stereo Rule

STEREO RULE illustrates one of the rules the brain follows for perceiving depth. Two vertical rods stand against a plain background. If you look with both eyes, it is clear that one rod is farther away than the other. If you look with one eye alone, the two rods appear to be side by side. However the distance between them depends on which eye one uses. The "stereo rule" uses this difference in distance to determine which rod is farther away. If the space between the rods appears greater using the right eye than it does when using the left eye, the rod on the right is farther away.
