1. A method for calibrating an estimated gaze location of a viewer of a display device, the method comprising: monitoring the estimated gaze location of the viewer using gaze tracking data from a gaze tracking system; receiving image data for display via the display device, the image data comprising a video that includes at least one target visual that traverses a predetermined path during a target timeframe and attracts a gaze of the viewer, and the image data comprising target visual metadata that identifies the at least one target visual in the video; without using another input from the viewer, identifying within the video the at least one target visual; without using another input from the viewer, using the target visual metadata to identify the target location of the at least one target visual; monitoring the estimated gaze location during the target timeframe; estimating a probability that the viewer is gazing at the target location; comparing the estimated gaze location of the viewer with the target location of the at least one target visual at a plurality of instances during the target timeframe; calculating an offset vector based on the estimated gaze location and the target location, and wherein calculating the offset vector further comprises utilizing the probability in calculating the offset vector; and calibrating the gaze tracking system using the offset vector to generate an updated estimated gaze location of the viewer.