preliminary This book addresses eye tracking research and methods in the context of computer-based visualization. Progress in hardware technology and the reduction of costs for eye tracking devices have made eye tracking accessible to a large population of researchers. Recording the observer's gaze can reveal how dynamic graphical displays are visually accessed and which information are processed in real time. Nonetheless, standardized practices for data analysis and interpretation remain unresolved. This book provides the recent developments in the corresponding interdisciplinary field spanned by research in visualization, eye tracking, human-computer interaction, and psychology. It contains extended versions of the papers from the First Workshop on Eye Tracking and Visualization (ETVIS), which was organized as a workshop of the IEEE VIS Conference 2015. These extended papers are complemented by longer chapters that provide a survey of state-of-the-art. The topics include visualization and visual analytics of eye tracking data, metrics and cognitive models, eye tracking experiments in the context of visualization interfaces, and eye tracking in 3D and immersive environments.