One of the motifs in the novel is that of moral judgment. Nick introduces this idea immediately in Chapter I when he explains that he grew up not judging others. Before the end of his introduction, however, Nick makes it clear that after coming back from the East, he had made a definite moral judgment concerning Gatsby and what "preyed" on him.
The eyes of T.J. Eckleburg on the old billboard overlooking the Valley of Ashes continue this motif. Inanimate and unseeing, they watch wordlessly over events as they unfold at Wilson's garage. Eckleburg sees all but judges nothing. This does not imply, however, that no judgment will be forthcoming.
The introduction of Owl Eyes later in the novel is suggestive of Eckleburg's eyes. Gatsby's guest, referred to as the "owl-eyed" man, wears the same style of round glasses as Eckleburg. At Gatsby's pitifully small funeral, Owl Eyes arrives unexpectedly. Standing in the rain, he makes a moral judgment in summing up the tragedy of Gatsby's life and his death. Owl Eyes calls Gatsby "The poor son-of-a-bitch." If Eckleburg could have spoken, considering what he had observed in the Valley of Ashes, he would have reached the same conclusion.
Doctor T. J. Eckleburg