**Review of Pupil**

Pupil is an accessible, affordable and extensible open source platform for ubiquitous eye-tracking and gaze-based interaction. Pupil's advantages are:

1. Light-weight eye tracking headset
2. an open source software framework for mobile eye tracking
3. A graphical user interface to playback and visualize video and gaze data. 
4. High-resolution scene and eye cameras for monocular and binocular gaze estimation.
5. Software and GUI are platform-independent and include state-of-the-art algorithms for real-time pupil detection and tracking, calibration, and accurate gaze estimation.