But his eyes, dimmed a little by many paintless days, under sun and rain, brood on over the solemn dumping ground
This line emphasizes the sadness associated with economic disparity in the Valley of the Ashes. The billboard with the eyes of Dr. T. J. Eckleburg was put there because there was some kind of hope for success. The “American Dream” influenced this man to advertise because he believed that anyone could make it, but years of neglect, “many paintless days”, of this sign show that this dream was not actualized. Now the billboard is faded and ignored further, just like this one.
Also, this line illustrates the indirect relationship between the upper classes and the Valley of the Ashes. The eyes looking out from the billboard were hoping to see customers and a chance for success, but now his eyes are “dimmed a little” because they instead look out over a “solemn dumping ground”. The words “dumping ground” emphasize the neglect of this area by the wealthy. While Gatsby is holding extravagant parties, the waste and trash from that pompous lifestyle is put in the place where the wealthy refuse to look: the poorer neighborhoods. The eyes of Dr. T. J. Eckleburg “brood” over these sad circumstances as he gets ignored, living through “many paintless days” of neglect.
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