Robert has developed certain strong personality traits just because of the fact that he can't see. Like all blind people, he has had to depend on others. This has caused him to develop trust in people, something lacking in the narrator, who reveals himself as suspicious, defensive, jealous, and slightly hostile.
The narrator doesn't like himself. He is an underachiever. He doesn't like his job. He is socially awkward. He has an inferiority complex. He has no religious faith. He has no friends. He has no children and is in danger of losing his wife, who is getting tired of his fecklessness and negativity. They live in a cheap apartment in some nondescript neighborhood. His only interests are in drinking, smoking marijuana, and watching television.
One reason the narrator is apprehensive about the blind man's visit is that he fears it will interfere with his routiine. He might not be able to drink as much as usual. He probably won't be able to smoke pot or watch television. He is prepared to dislike Robert because he suspects that his wife has a better relationship with this blind man than she has with him, even though she hasn't actually seen Robert in ten years. The narrator feels certain that in all their taped correspondence, his wife must have revealed a lot of unpleasant truths about her husband.
Robert's visit threatens to cause further domestic friction. Even before the blind man gets there, the narrator is making little jokes that reveal his uneasiness, jealousy and hostility.
"Maybe I could take him bowling," I said to my wife. She was at the draining board doing scalloped potatoes. She put down the knife she was using and turned around.
(It is a nice Carveresque touch that the wife puts down her knife before turning around. She doesn't want to look menacing.)
"If you love me," she said, "you can do this for me. If you don't love me, okay. But if you had a friend, any friend, and the friend came to visit, I'd make him feel comfortable." She wiped her hands with the dish towel.
The biggest contrast between narrator and guest is that the narrator is shy, awkward, unsure of how to play the role of host, whereas Robert is relaxed and affable. The blind man not only has had to trust others but has learned that most people are basically kind and decent.
Whatever fears the narrator had about Robert's disrupting his routine, he quickly gets over them. It is as if the blind man can only see the good and likable part of his host. Robert likes to drink. He is willing to try smoking pot. It turns out that he not only likes television but actually owns two sets. The reader can feel the narrator opening up with this friendly stranger. The culmination of the evening occurs when the narrator turns on the television set and has to try to describe to the blind man what he is seeing.
I said, "The truth is, cathedrals don't mean anything special to me. Nothing. Cathedrals. they're something to look at on late-night TV. That's all they are."
Any reader looking for grand epiphanies and resolutions in Carver's stories is doomed to disappointment. The two men end up symbiotically drawing a cathedral on a paper bag, symbolizing the spiritual alienation of modern man. Their moment of intimacy is a pathetic contrast to the powerful religious faith that inspired men in the Middle Ages to cooperate for decades in creating their cathedrals. Carver intentionally ends his story with a characteristic understatement.
"It's really something," I said.