• Accommodationthe refocusing of the eyes as their vision shifts from one distance plane to another.
  • Complementary colorsthe meeting of lines of sight through the eyes, or light rays through the optical system, at a common point closer than infinity.
  • Convergence – converging sight lines while looking at objects located at a small distance.
  • Parallax the differences in a scene when viewed from different points. In stereo,often used to describe the small relative displacements between homologies, also termed deviation.
  • Stereo basethe distance between positions of taking left and right photos or between the leftmost and rightmost frames in multi-frame series.
  • Stereo pair – two photos of the same scene (object) taken by two identical cameras from two different points horizontally distanced from each other (at the stereo base distance).
  • Separation (interaxial) the distance between two taking positions in a stereo photograph. Sometimes used to denote the distance between two homologies.
  • Zero parallax object (zero parallax point) object in the image, which both eyes perceive equally, without any deviation. Actually, according to this object will be evaluated the distances to other objects. Usually, it is the object that your eyes are focused on.