Abstract: Eye gaze, often regarded as a language of non-verbal communication can be studied and estimated using scientific detection methods and contains a tremendous scope of applications in daily lives. Investigations in eye gaze detection can give ideas about what a person is thinking about based on how and where he is looking. Nowadays, the eye gaze detection methods utilize an incorporation of convenient hardware and affined software to detect the gaze direction for providing new applications ranges. In this study, the objective is to provide an inclusive expansion in classifying the recently existing methods based on the eye gaze detection by considering various paradigms such as wearable and unwearable devices, active and passive systems, feature and appearance approaches, the estimation of head movements and the used algorithm. This study includes the major preliminaries, usefulness and abuses as well as the necessities of future expansion in the domain.