Magnificent Obsession (1936)

The life of spoiled Robert Merrick (Robert Taylor) is saved through the use of a hospital's only pulmotor, which results in the death of Dr. Hudson, a selfless, brilliant surgeon and generous philanthropist. Merrick falls in love with Hudson's widow, Helen (Irene Dunne), though she holds him responsible for her husband's demise. One day, he insists on driving her home and makes a pass at her. She gets out and is struck by another car, losing her sight.
He watches over her and visits her during her recuperation, concealing his identity and calling himself Dr. Robert. When he finds out that she is nearly penniless, he secretly pays for specialists to try to restore her vision. Finally, she travels to Paris and is told that her eyesight is gone forever. Robert follows her, confesses his true identity and proposes marriage. She forgives him, but goes away, not wanting to be a burden to him.
Years later, Robert has become a brain surgeon. He learns that Helen urgently needs an operation, which he performs. When she awakens, her sight has miraculously returned.