A selling server stores prescription data of a customer transmitted from an optometrist terminal of an optometrist who performs optometry for a glasses prescription through a communication line in association with customer identification information, transmits image data of a frame candidate group of glasses to a customer terminal, transmits image data of a lens candidate group of the glasses to the customer terminal, receives information relating to a frame and a lens purchased by the customer and determined on the basis of a combined image of a frame image selected by the customer, a lens image selected by the customer, and a face image of the customer, and transmits prescription data of the customer to a lens company terminal of a lens company which processes the lens purchased by the customer.