The visual cortex is the largest and busiest part of the brain. There's no doubt Homo Sapiens is an animal that relies heavily on sight. We take it for granted, living as we do surrounded by the rich visuals of the reality we have constructed, that to see is EVERYTHING. But, while the "food of the eye" has arguably never been saltier or contained so many empty calories, its ravenous appetite is as old as the species. Needless to say, the importance of our Sense of Sight could not have evolved overnight.