An important question is what advantages does binocular vision provide in the real world? As a visual effect it clearly fascinates the majority of people when they see a 3D picture. Beyond the attractive nature of stereoscopic 3D images they provide the following beneﬁts over monocular vision:
• Relative depth judgement. The spatial relationship of objects in depth from the viewer can be judged directly using binocular vision.
• Spatial localisation. The brain is able to concentrate on objects placed at a certain depth and ignore those at other depths using binocular vision.
• Breaking camouﬂage. The ability to pick out camouﬂaged objects in a scene is probably one of the key evolutionary reasons for having binocular vision.
• Surface material perception. For example, lustre, sparkling gems and glittering metals are in part seen as such because of the dfferent specular reﬂections detected by the left and right eyes.
• Judgement of surface curvature. Evidence suggests that curved surfaces can be interpreted more effectively with binocular vision.
These beneﬁts make stereo image display of considerable beneﬁt in certain professional applications where depth judgement is important to achieving successful results. In addition the effect of stereopsis is compelling enough that stereoscopic images form the basis of many entertainment systems.