I read a book as a teenager in the '70s, which had a short one-word title as I remember it, in which the hero is rendered blind at some point, but achieves his mission by 'hitch-hiking' into other heads and using their eyes, shifting from one to another as he nears his goal. This is all very vague, but it was a long time ago! Any clues as to what I'm talking about?
It might be Night Walk by Bob Shaw (1967).
From the Wikipedia article, emphasis mine:
He is blinded when Cherkassky shoots him in the face with a dart gun, destroying his eyes. He is taken to a secret prison complex in the southernmost tip of the most distant continent to convalesce. While he is there, he enlists the aid of the scientific elite among the other political prisoners there, and together they design a pair of electronic "sonar" eyes. The headgear delivers different tones to distinguish various objects. Later, they make another breakthrough: they make a device that can sense and interpret the nerve signals of the eyes of nearby living things. Tallon can now see, but only through others' eyes. After they develop and test this device, Tallon and his partner Winfield try to break out, but Winfield is shot during the attempt. Tallon must flee alone, depending on encountering local animal life in order to see.