Existing approaches for mobile authentication are prone to shoulder-surfing and side-channel attacks. Using gazes for authentication has been demonstrated to be more resistant to these attacks. Yet, existing solutions rely on eye-tracking by the device's front camera that is not always reliable. In this paper, we present an approach for EOG-based authentication by determining the gaze-based on the electronic potential of the eyes. Our approach runs on commercially available smart glasses and there is no need for the user to look at the device. Through a user study with 15 participants, we demonstrate the feasibility of the approach, its usability, and its adoption by mobile device users. Even users without regular glasses would adopt EOG-based authentication.