A modern view on paradoxes in binocular perception

Visually-guided behavior can be hampered, as well as facilitated, by the difference of the images observed with the right and the left eye. This duality is clearly manifested in such actions as aiming and grasping. Correspondingly, the theories of binocular vision include both the concept of temporary blocking one of the two visual inputs to the brain and the concept of a useful combination of the signals provided by the two eyes.
When the mechanisms of binocular perception are studied experimentally under dichoptic viewing conditions, the researcher is often confronted with seemingly paradoxical effects, such as an illusory disintegration of the perceived objects, surrealistic combinations of their fragments, phantom images, inversion of the mutual positions of the visual stimuli, or continuous change in a perceived image of a stationary scene. These paradoxes are known to affect a wide range of visual properties including brightness, colour, shape, direction, and depth.
For a long time, even the simplest of these phenomena defied explanation, because it was poorly understood how the brain processes signals transmitted by the two eyes. However, most of these paradoxes are being resolved now due to dramatic progress in our appreciation of the sophisticated structure and functional organization of the human binocular visual system, with its parallel pathways where various channels of information transmission and processing are engaged in co-operative as well as competitive relationships at several levels.