When a meridional lens is oriented axis vertical before one eye, the horizontal magnification produces a tilting of visual space in the third dimension which is predictable from the geometry of binocular parallax. When, however, the lens is oriented axis horizontal so that the magnification is vertical, a distortion of space occurs which is similar to the tilting caused by the presence of a lens oriented axis vertical over the other eye. It has commonly been believed that this phenomenon, known as the induced size effect, has no geometric explanation, and is an anomalous stereoscopic response to vertical disparities. An explanation is presented which accounts for the induced effect in terms of actual horizontal disparities between vertically magnified oblique lines, and disparities of the two-dimensional spatial spectra of the two eyes.
ASJC Scopus subject areas
- Sensory Systems