The horopter is a spatial representation of all points in space imaged on corresponding retinal points in the two eyes. Which option completes this definition?

The horopter is a spatial representation of all points in space imaged on corresponding retinal points in the two eyes. Which option completes this definition?

• A. Corresponding retinal points
• B. Non-corresponding retinal points
• C. Foveal points only
• D. Peripheral points

Answer: (A)

The important idea here is that the horopter consists of points in space that image on corresponding retinal points in the two eyes. When an object lies on this locus, its images line up on the same relative positions on both retinas, so there is no binocular disparity and the brain fuses the two images into one. That’s why points on the horopter produce single, fused vision. Points off this locus create retinal disparity because they stimulate non-corresponding points in the two retinas, and the brain uses that disparity as a cue for depth. The horopter isn’t limited to the fovea or to peripheral regions; it includes a range of points around fixation that share the property of stimulating corresponding retinal points.

The important idea here is that the horopter consists of points in space that image on corresponding retinal points in the two eyes. When an object lies on this locus, its images line up on the same relative positions on both retinas, so there is no binocular disparity and the brain fuses the two images into one. That’s why points on the horopter produce single, fused vision.

Points off this locus create retinal disparity because they stimulate non-corresponding points in the two retinas, and the brain uses that disparity as a cue for depth. The horopter isn’t limited to the fovea or to peripheral regions; it includes a range of points around fixation that share the property of stimulating corresponding retinal points.