Eye tracking has evolved and become more widespread in recent years. Devices have become more robust and the user interfaces more diverse. Eye tracking in therapy and rehabilitation enables greater autonomy and independence, even in cases of severe physical limitations. The reason for this positive development is new areas of application for eye tracking. Virtual games and simulations that use eye-based modeling alone represent two very large and profitable areas. This essay describes the current development and dissemination of this technology and presents the freely available materials from the EyeTrack4all research project. It then examines new areas of application for eye tracking in medical diagnostics and therapy, as well as in pain treatment and rehabilitation.