A method of producing an optical sensor at wafer-level, comprising the steps of providing a wafer having a main top surface and a main back surface and arrange at or near the top surface of the wafer at least one first integrated circuit having at least one light sensitive component. Furthermore, providing in the wafer at least one through-substrate via for electrically contacting the top surface and back surface and forming a first mold structure by wafer-level molding a first mold material over the top surface of the wafer, such that the first mold structure at least partly encloses the first integrated circuit. Finally, forming a second mold structure by wafer-level molding a second mold material over the first mold structure, such that the second mold structure at least partly encloses the first mold structure.