try following texts from art historian Ernst H. Gombrich:
 
- Art and illusion : a study in the pictorial representation, Pantheon
books New York, NY, copyrighted 1960
 
- The image and the eye : further studies in the psychology of pictorial
representation, Phaidon Oxford, 1982
 
they're not too difficult to read.
 
sincerely
 
Meret Ernst
 
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