The narrator describes "the sleeping ones" thoroughly in the Prologue. His "invisibility" occurs due to "a peculiar disposition of the eyes of those with whom I come in contact." However, it is not their actual eyes to which the narrator refers, but "their inner eyes." These are the eyes that they use to "look through their physical eyes upon reality." These people have "poor vision" and, like those with literally poor vision, they are constantly bumping into others—metaphorically, black people—and not seeing them, as though they do not really exist.
In other instances, the narrator feels like a creature from a "nightmare" whom a "sleeper" tries to destroy. His physical confrontation with a tall, blond, blue-eyed man who bumps into him and insults him mirrors this. The man does not see the narrator, but curses him for his physical presence. The blond man is a specific example of a "sleeper" or one of the "sleeping ones"—people, white people we infer, who do not see the narrator because he is a black man, or a figure of the "near darkness." In the passage the "darkness" symbolizes the nightmarish or unbearable visions that racism has created in the white imagination. Furthermore, the narrator's lack of visibility is contrasted with that of a tall, blond, blue-eyed man, someone who would be very much recognized in a culture that values and centers around white people.