Disclosed herein a device tracking gaze and method therefor. The device includes: an image acquisition unit configured to obtain an eyeball image; a pupil detection unit configured to detect a center of pupil by using the eyeball image; a virtual corneal reflection light position generator configured to process the eyeball image so that a virtual corneal reflection light is located at a predetermined point in the eyeball image; and a PCVR vector generator configured to generate a pupil center virtual reflection vector (PCVR vector) based on a position of the pupil center and a position of the virtual corneal reflection light.