Peter Wilson (Jack Lemmon) is a sarcastic near-sighted cartoonist, author and swinging bachelor living in Manhattan. He detests women, dogs, and children. He is flustered by women's priorities and avoids commitment, much preferring transient physical relationships. At the office of his eye surgeon, Peter meets a leggy, eye-catching strong-willed woman named Terri Kozlenko (Barbara Harris). He likes her very much, but discovers later that she is a single mother to three children, Caroline, Linda, and David. The first thing she learns about him, from his ophthalmologist, is that he's in danger of losing his sight, which would make it impossible for him to continue his work.