An image system for surgery includes: a three-dimensional imaging unit acquiring two images having parallax by capturing an image of a portion a display unit displaying two images acquired by the three-dimensional imaging unit individually for both left and right eyes, or displaying a same image for both left and right eyes a detection unit detecting that a treatment device that performs treatment on the portion or the three-dimensional imaging unit is in an operating state in which to initiate treatment on the portion and a display control unit switching from displaying one of images on the display unit to displaying two images on the display unit when the detection unit detects the three-dimensional imaging unit or the treatment device is in the operating state in which to initiate treatment on the portion.
