The narrator of "The Cathedral" starts by describing the imminent arrival of an old acquaintance of his wife. The man, Robert, is blind, and the narrator's wife used to read for him. She knew Robert before she married the narrator.
Before she and Robert said goodbye ten years before, Robert asks to "read" her face with his fingers. This is a life-altering experience for the narrator's wife, but the narrator has no understanding how this could be of any significance.
There is no indication that there was anything other than a platonic relationship between the Robert and the narrator's wife. Robert, in fact, has recently lost his wife, who he dearly loved, and is traveling to visit with her family.
Basically, the narrator is a childish brat. He is unhappy about the impending visit, acting as if he is jealous--and perhaps he is in that his wife and this "disabled" person have shared something he, a healthy and whole person, had no part in, and cannot appreciate.
The narrator is unsympathetic towards Robert's plight, callously discussing how Robert's dead wife had to deal with a husband who could not see her face. The reader gets the sense that the narrator perceives himself as someone superior to Robert, most particularly because of Robert's infirmity.
When Robert arrives, the narrator has little to say, as if sulking.
Next the narrator turns on the television, an extremely rude and uncaring thing to do, not only in the presence of a guest, but a blind one at that. The narrator's wife is appalled and embarrassed.
After his wife falls asleep, the narrator and Robert continue to "watch" the TV. The narrator describes what is on the screen until a story appears about a cathedral. The narrator is at a loss as to how to describe it with words.
Robert suggests that the narrator get a pencil and paper so "they" can draw. With the narrator's hand in place, Robert puts his hand on top and follows the narrator's hand as he draws.
During this time, Robert tell the narrator to close his eyes, and something dramatically changes in the narrator. Instead of being aware of the confines of his own house, the walls and doors, the narrator has a sense of not being contained in anything, but being open to the world.
The narrator's jealousy and hostility toward Robert vanish. He understands life in a new and wonderful way, experiencing something completely unique to what he has known of the world until now. He is no longer aware of Robert's blindness, and has hope that he may be able to change his life.
The narrator's narrow-minded perceptions of, and attitudes toward, Robert change dramatically throughout the story. He starts out by being "blind" in his own way, and through some miracle is given the rare gift of "sight" regarding the things in life that really matter, and his entire attitude changes with the possibilities of change that stand before him now.