Psyche 59

Following a serious fall, Allison (Patricia Neal) loses her sight. Though doctors insist that her blindness is psychologically induced, Allison has no memory of the events leading up to the incident, so her condition persists. When her attractive younger sister, Robin (Samantha Eggar), comes to visit, Allison senses a tension between her husband, Eric (Curt Jurgens), and Robin. As a long-buried memory of Eric's infidelity emerges, Allison's vision returns -- a fact that she keeps to herself.