[Object] To provide a control system, an information processing device, a control method, and a program capable of capturing a clear iris image having no reflected light of illumination without interfering with a user's field of view.[Solution] A control system including: an illumination section configured to irradiate any one of left and right eyes with light; an imaging section configured to image the other eye different from the one of the left and right eyes; and a control section configured to perform control to cause the imaging section to image the other eye while the illumination section is irradiating the one of the left and right eyes with light.