What we see is not an image like a camera, what we see is a datafusion of myriad brain centres, each speciallized in some particular part of seeing has gestalted for our conciouswness according to a learned set of rules from infancy. Some parts see contrast, others motion, edges, texture, parallax, focus, etc. Other parts take these and begin to composite some of them, such as colour and contrast (how we can tell a certain shade of a colour under various lighting sources is partially infered from surrounding context and contrast as an example) an example of the rules based interpretation is If i reach outside the edge detected, I will not encounter the object. Sight is a really Non simple thing and to answer an earlier comment/question - No you do not see the same colour as everyone else. Vision is unique to each individual so your colour (as gestalted from a certain stimulus driven datafusion uniquely hardwired into your brain) is interpreted by rules you evolved as a baby/child from physical experimentation and societal consensus training cannot be the same but will appear so at the macro and societal level. Help, I need a pub!

Pass no temptation lightly by, for one never knows when it may pass again!