Rely on 2 eyes: each eye sees the world from slightly diferent perspecives. Binocular disparity (reinal disparity: diference between the right and let eye"s vision. Stereoscope: two diferent pictures taken at diferent points of views, given at the same ime, will give the impression of 3d. Determine what on the let eye image corresponds to the image on the right eye. Auto-stereograms: depth illusions caused when we solve the stereo- correspondence problem incorrectly, can occur when there is repeiion in images. Misatribute image of 2 idenical objects to be the image of one single object. Reinal disparity: diference in posiion of let/right eye. 3 possible outcomes (horopter ixaion plane: items on the horopter. Image is on same posiion in both eyes: items in front of the horopter (crossed dispariies) Image is on same posiion on opposite sides of the reference points: items behind the horopter (uncrossed dispariies) Image is in diferent posiions on the same side of the.