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We cannot see an object which is farther from use than about 3500 times its size 
In general field of view has irregular conical shape , measuring about 30 degree up  , 45 degree down, 65 degree to each side. 


Maximum distance
Maximum distance for seeing people is 4000 feet
Maximum distance for discerning action is 450 feet
Maximum distance for recognizing a face is 80 feet 
Maximum distance for discerning facial expression is 40 feet 
Range of conversational distance is 3 feet to 10 feet