Systems and methods to monitor and interact with users viewing screens are disclosed. An example system includes a sensor to gather gaze data from a user viewing images on a display. The display has spatial coordinates. The system includes a processor communicatively coupled to the display and the sensor. The processor determines a first gaze location having first spatial coordinates based on the gaze data and calibration settings associated with determining gaze locations. The processor alters a portion of the display at or near the first gaze location. After the portion of the display has been altered, the processor determines a second gaze location having second spatial coordinates based on the gaze data and the calibration settings. The processor performs a comparison of the first gaze location to the second gaze location. If the comparison does not meet a threshold, the processor updates the calibration settings based on the comparison and determines a third gaze location having third spatial coordinates based on the gaze data and the updated calibration settings.