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I went back to my psychology book from the course Behavioral Neuroscience, "Physiology of Behavoir" by Carlson, and looked at the chapter on vision.  At the start of each chapter there is a description of a particualr case study.  For this chapter, Mrs. R was the patient.  She had suffered a stroke that affected her vision.  She could not identify objects, but could describe the object by it parts.  (A wristwatch was put in front of her, she knew it was a circle with two things attached at the top and bottom, but couldn't come up with the word, 'watch.')  As soon as she picks up an object and feels it, she can identify it.  She can only identify people by the sounds of their voice and the way they walk, not their faces.The sensory receptors in Mrs. R's ears (hearing) and hands (touch) obviously still are completely in tact, but one step of communication between her eyes and her brain is broken.  There must be multiple levels of processing to interpret the picture on the retina of the eye.  Looking at the case of Mrs. R. there must be at least one level to identify the parts of an object, and another to put a name and function to the object.  There is probably another whole section that processes movement and putting names and functions to those movements (this pathway seems to be unaffected in Mrs. R.)Recognizing what you see is not a simple process; there are different levels of processing and different pathways.  It will be interesting to see in the upcoming lectures to see how our brains can make a comprehensible picture entirely different from the image on the retina.  The brain must play tricks on us.  The picture in our head is really only nominally related to the picture in on our eyes. Going a step further, the picture I have in my brain, and the picture in yours must be really different purely based on the fact that the initial image must go through many steps in processing.  And when there are a lot of steps, there's a lot of room for differences from person to person.What do you see?