A system and techniques for calibrating an eye tracking system are described. The system can update the calibration of personal calibration parameters continuously based on a user's gaze on a user interface, following user interface stimulus events. The system improves continuous calibration techniques by determining an association between the user's eye sequences and the stimulus events, and updates the personal calibration parameters accordingly. A record indicative of a user gaze, including eye sequences, such as eye movements or eye fixations, is maintained over a time period. A user interface stimulus event associated with the user interface and occurring within the time period is detected. An association is determined between the eye sequence and the user interface stimulus event. An interaction observation that includes the eye sequence and a location of the stimulus event is generated. Personal calibration parameters are updated based on the interaction observation.