(and a discussion of the ash heaps)
T.J. Eckleburg is an optician / optometrist / oculist (Fitzgerald's most-used choice) / metaphor in The Great Gatsby. He never appears in person in the book; he is only spoken of once outside of the narration. However, his eyes appear, blown out of proportion, on a billboard over the railroad from West Egg to New York.
Eckleburg is a symbol for the futility of life which the lower classes endure in the ash heaps, halfway between the luxury of Long Island and the city. Fitzgerald refers to the people there as being themselves composed of ash, living fleetingly and meaninglessly while surrounded by wealth. He is described as having forgotten the advertisement which he placed there; his eyes remain to "watch over" the landscape.
"... above the gray land and the spasms of bleak dust which drift endlessly over it, you perceive, after a moment, the eyes of Doctor T. J. Eckleburg. The eyes of Doctor T. J. Eckleburg are blue and gigantic - their retinas are one yard high. They look out of no face, but, instead, from a pair of enormous yellow spectacles which pass over a non-existent nose. ... But his eyes, dimmed a little by many paintless days under sun and rain, brood on over the solemn dumping ground."
F. Scott Fitzgerald
uses the word "paintless" in the preceding passage, the first in the book mentioning the good doctor, to allude to "pointless
"; the reader's first impression forces him to read the passage
again. Nick speculates to the reader that Eckleburg's fate was "to sink
down himself into eternal blindness, or forgot them and moved away." 'Them' refers to the eyes
themselves, rather than the billboard, further reinforcing their importance.
Two popular metaphors exist for the eyes. The "American Dream" school of thought supposes T. J. to be an allusion to Thomas Jefferson, seen as a guardian of the American workers and farmers, despite his own aristocratic status. Jefferson does not watch over the rich, immoral families of the Jazz Age, but the mechanics and craftsmen of the ash heaps.
Another, easier metaphor is that Dr. Eckleburg's eyes are the eyes of God, guarding over his forgotten children who suffer endlessly in meaningless lives. The American Dream metaphor is more popular, since it fits with the more traditional themes of the book, among which religion does not appear. However, one major passage supports this claim. Towards the end of the book, as Wilson rages over the unfortunate events (which I will not reveal), he says:
"... and I said 'God knows what you've been doing, everything you've been doing. You may fool me, but you can't fool God!' "
Wilson sees Eckleburg's eyes as a bringer of vengeance against the unjust, and a symbol of the oppression which he endures due to Tom Buchanan and the other wealthy residents of East Egg.
Standing behind him, Michaelis saw with a shock that he was looking at the eyes of Doctor T. J. Eckleburg, which had just emerged, pale and enormous, from the dissolving night.
"God sees everything," repeated Wilson.
Whatever the appropriate theory, Eckleburg's eyes figure prominently into the novel and life in the ash heaps in which Fitzgerald placed some of his most and least admirable characters.
Sources: All of my English teachers (thanks, guys).