The act of vision


(The same basic principles as discussed below apply accordingly   to other pathways providing sensory input as well.)




The act of vision is a multitask event involving the entire nervous system.




  Most objects will produce on the retina an optical impression bouncing continuously around unless eyes and object are in fixed position.

From these optical impressions involving both eyes a single central image is created, facilitating further data-integration as well as object re-identification.

This vision transmitted information is interconnected with information acquired by other means, thus contributing to a multi-located data-base.




  To keep the object in view while in motion requires moving the eyeballs, head, neck, trunk, eventually the entire body, thus involving a mayor part of the entire nervous system just to execute this position-locating task.

Whereas the main function of the outer part of the retina is essential to register objects, the central part, exhibiting a much higher power of resolution, has in addition the task to generate more detailed information.

As the eye is not conceived as a single-task optical instrument, the images produced do not relate to standards such as established for various forms of D3-D2 projections, presenting eventually as funny, amazing optical illusions.

Already in the early phase of the creation of the central image, information is transmitted and shared with brain-areas associated with early-danger-alert, recognition of failure or success of object-identification and others, functions accelerating the decision-making process. Not reaching necessarily the sphere of consciousness, this information may have considerable modulatory impact.

The spreading of emotion related information is nicely expressed in terms such as "breathtaking beauty", "frightened to death", “shaken to the bone” and others.




  The act of vision is a far more complex procedure than just establishing an internal image of an external object. In fact during this entire process the mind is telling the rest of the brain and the body in addition for what to be prepared for to do next, e.g. to pre-adjust the position of the eye to where the object - say a bird - is likely to appear next, to focus then immediately on the pick to confirm if it is indeed very short and red, to be prepared to keep quiet to listen to the bird's song etc.. The ability to establish “plans of action” is essential for the mind to work efficient.