Psyche 59 (1964, U.K.)

Although the doctors can find nothing wrong with her eyes, Alison (Patricia Neal) remains blind following a fall down stairs during the waning months of her pregnancy. When Alison tells her husband, Eric (Curt Jurgens), of an upcoming visit by her newly divorced younger sister, Robin (Samantha Eggar) he’s angry.

But once Robin arrives and sees that her brother-in-law is attracted to her, she deliberately sets out to seduce him, despite the presence of her sightless sister.