I Love Lucy (1951)

Season 3: Episode 11

Lucy finally gets her chance to be in show business, when she tricks Ricky into letting her do the "Jitterbug" in one of his shows. She's terrific during rehearsals, but problems occur when Lucy accompanies Ricky (who's been suffering from headaches) to the eye doctor just before the show. There, the doctor decides to examine Lucy's eyes, as well. He puts some eyedrops in Lucy's eyes which "relaxes" them, but Lucy's vision is blurry for the next twenty four hours. Naturally, this causes problems since Lucy has to perform that night.