What are patterns in the story "Araby" that show relevance to light, vision and beauty?

The passages of the story "Araby" that bear most relevance
to the themes of light, vision, and beauty are those dealing with Mangan's sister.  To
summarize the story's viewpoint, Mangan's sister is attractive to the boy because she is
only half-illuminated to him, both literally and physically.  When she appears in the
doorway, the light only hits the curve or her neck and "one side" of her dress;
correspondingly, the entire setting of the story (the boy's entire world), North
Richmond Street, is described as "blind."  Though Mangan's sister is the focus of the
story, Joyce does not give her a name or a concrete physical description; she is only
described as "brown" on some occasions, and "white" on others.  At the center of the
story, the boy says, "I was thankful that I could see so little."  This proves to be a
defining statement once he arrives at the Araby bazaar and actually watches a
flirtatious interaction between a shop girl and two male customers.  Upon seeing what
appears to him to be the frivolity of dating and romance (as opposed to the chivalrous
romantic quest he imagined it to be).  Upon actually being confronted with and "seeing"
romance for what it is, his eyes begin to burn with tears, and the charade of Mangan's
sister (resulting from his inability to "see" her, or to interact with and understand
her as other than a symbol) ceases to exist.