The Cay by Theodore Taylor

Phillip was so frightened he could hardly breathe. All around him were the shark-infested waters of the Caribbean...and the darkness.Blinded be the blow to his head when the ship was torpedoed, he was a drift on a wooden raft with the big old black man who worked on deck.

Cast up on a remote and barren island, they begin an amazing adventure. One that allow Phillip to "see" for the very first time, how blind he had been before he lost his sight and experienced the kindness, wisdom, and love of a simple extraordinary man.