Which term is the area around a corresponding retinal point where objects are still seen as single and in depth?

Which term is the area around a corresponding retinal point where objects are still seen as single and in depth?

• A. Panum's fusional area
• B. Panum's fusional space
• C. Horopter region
• D. Fusion envelope

Answer: (A)

The main idea is how the brain tolerates small mismatches between the two eyes to keep vision single. Panum's fusional area is the region around a corresponding retinal point within which the images from the two eyes can be fused into one percept, and this fusion can still convey depth from the remaining disparity. Objects inside this zone appear single, and the slight differences between the two images give rise to stereopsis. If the disparity is too large and falls outside this area, the images cannot be fused and diplopia occurs. The horopter is a related concept describing the set of points in space that map to corresponding retinal points (zero disparity), which yields single vision but not the same depth cue from disparity. Fusion envelope is not a standard term, whereas Panum's fusional area is the established name. So the described term is Panum's fusional area.

The main idea is how the brain tolerates small mismatches between the two eyes to keep vision single. Panum's fusional area is the region around a corresponding retinal point within which the images from the two eyes can be fused into one percept, and this fusion can still convey depth from the remaining disparity. Objects inside this zone appear single, and the slight differences between the two images give rise to stereopsis. If the disparity is too large and falls outside this area, the images cannot be fused and diplopia occurs. The horopter is a related concept describing the set of points in space that map to corresponding retinal points (zero disparity), which yields single vision but not the same depth cue from disparity. Fusion envelope is not a standard term, whereas Panum's fusional area is the established name. So the described term is Panum's fusional area.