Ans:-The eyes of the narrator’s co-passenger is referred to here. The eyes were not useful to her because she was completely blind.
From the start of the journey the narrator pretended to the girl that he was not blind. But when he asked the second co-passenger if the girl had kept her hair short or long, the man replied that he did not notice the girl’s hair. He only noticed the beautiful eyes of the girl which were of no use to her as she was completely blind. The irony of the situation is that the narrator was trying to hide his blindness from the girl who was also blind.