An unlock procedure for an electronic device can be based at least in part upon a determined gaze direction or viewing location of a user. During a device unlock process, the user can be directed to follow an element or path on a display element with the user's eyes. Image information captured of the user during this process can be used to correlate the user's eye position in the image with the corresponding gaze location on the device, in order to calibrate the gaze tracking in a way that is substantially transparent to the user. Further, certain devices can also utilize captured image information during the unlock process to authenticate the user using a process such as iris recognition or retinal scanning. Such an approach enables secure access to the device without requiring the user to manually enter identifying information, and re-authentication can be performed without distracting the user.