Discuss the juxtaposition of light and dark imagery in "Araby." What is the significance of the contrast?

In "Araby," light seems to symbolize innocence and the hopefulness that attends it, while dark stands for the state of having lost one's innocence and the cynicism that such a state breeds.  When the narrator describes his boyhood, playing outside at night, he describes the darkness of the city streets about him but focuses on the way their "bodies glowed" as well as how Mangan's sister's "figure [was] defined by the light" from the door.  Though they are surrounded by darkness, the children are still innocent and therefore they are characterized by light.  Further, Mangan's sister, the subject of the narrator's young love, is also characterized by light because of his intense hope surrounding his feelings for her and the happy possibilities he associates with those feelings, especially after she speaks with him about Araby.

Though it is late and dark when the narrator finally leaves for the Araby bazaar, and though he is frustrated by his uncle's tardiness and the slowness of the train, he notices the streetlights "glaring with gas," the "twinkling river," and the "lighted dial of a clock."  Again, he is surrounded by darkness but only seems to notice the light because he is so wrapped up in his hopefulness about finding a gift for his love. However, when he gets inside the bazaar, most of the hall is "in darkness" and he goes through the one open stall's "dark entrance," looking at the disappointing wares before moving on.  The bazaar was really only full of English teacups and vases, staffed by a young English woman who seemed more interested in flirting than paying attention to her young customer.  Finally, the "upper part of the hall [became] completely dark," and standing in the darkness, the narrator has an epiphany: that the world doesn't care about him and his love, that love is not what makes the world turn.  Up until now, he was mostly aware of the light, he now becomes very aware of the dark, and he cries to think of his "vanity," that the dark world would make room for his feelings.  Therefore, the contrast between light and dark, and especially how much of each the boy seemed to notice at various moments, helps to develop the theme of the story.