Eyes allow us to see and gather information about the environment. Eyes mainly act as an input organ as they collect light, but they also can be considered an output organ as they indicate the subject's gaze direction. Using the orientation of the head and the position of the eyes, it is possible to estimate the gaze path of an individual. Gaze estimation is a fast growing technology that track a person's eyes and head movements to "pin point" where the subject is looking at on a computer screen. The gaze direction is described as a person's line of sight. The gaze point, also known as the focus point, is defined as the intersection of the line of sight with the screen. Gaze tracking has an infinite number of applications such as monitoring driver alertness or helping track a person's eyes with a psychological disorder that cannot communicate his/her issues. Gaze tracking is also used as a human-machine interface for disabled people that have lost total control of their limbs. Another application of gaze estimation is marketing. Companies use the information given by the gaze estimation system from their customers to design their advertisements and products. / Electrical and Computer Engineering