Shadowed Eyes (1940)

In this crime drama, a renowned eye surgeon goes mad and murders the lover of his wife. He is later given a life-sentence to be spent in a mental hospital. He thinks he truly is in for life, but then his assistant busts him out so he can save the eyesight of the prosecuting attorney (the assistant's father) who put him there. The operation is successful, but does not go without a hitch as the doctor again goes bananas for a time. Later his loyal assistant continues to try to get the doctor released.