Eye tracking is a process that identifies a specific point in both space and time that is being looked at by the observer. This information can also be used in real-time to control applications using the eyes. Recent innovations in the video game industry include alternative input modalities to provide an enhanced, more immersive user experience. In particular, eye gaze control has recently been explored as an input modality in video games. This book is an introduction for those interested in using eye tracking to control or analyze video games and virtual environments. Key concepts are...