DualGaze: Addressing the Midas Touch Problem in Gaze Mediated VR Interaction Pallavi Mohan 1 * Wooi Boon Goh 1† Chi-Wing Fu 2 ‡ Sai-Kit Yeung 3 § 1 Nanyang Technological University, Singapore 2 The Chinese University of Hong Kong, Hong Kong, China 3 The Hong Kong University of Science and Technology, Hong Kong, China ABSTRACT With the increasing acceptance of eye tracking as a viable interaction method for Virtual Reality (VR) headsets, thoughtful gaze interaction methods need to be carefully designed to meet common challenges such as the Midas Touch problem, where users unintentionally select onscreen objects by gazing upon them. This paper presents DualGaze, a novel interaction method in which users perform a distinctive two-step gaze gesture for object selection. Once users gaze upon an object that they wish to select, a confirmation flag pops up next to the object at a location where the users’ gaze just passed through. This trajectory-adaptive flag placement strategy reduces the chance of unintentional confirmation by requiring a returning gaze back to the flag. We conducted a user study to compare the accuracy and selection speed of DualGaze and the popular gaze fixation method on a simple gaze-typing task. Our results show that DualGaze is significantly more accurate while maintaining a comparable selection speed that was observed to improve with familiarity of use. Keywords: virtual reality, interaction methods, gaze interaction, Midas touch, eye tracking Index Terms: H.5.2 [Information Interfaces and Presentation]: User Interfaces—Interaction styles 1 INTRODUCTION In their confined setting, conventional VR headsets provide only limited input modalities. Commonly-supported interaction methods include tracking the user’s head orientation, external controllers and buttons, and more recently, gaze interaction by eye tracking. While gaze interaction is mostly used as an auxiliary input modality in regular desktop environments, with the current dearth in input modalities for immersive VR setups, it seems like a natural candidate for primary user input control. Hence, new and thoughtful mechanisms are needed to address common problems that the users faced in gaze-based interaction. One such problem is the Midas Touch [1], where users may unintentionally select an user interface (UI) element, e.g., a button, by accidentally looking at it. Common existing solutions to the problem include the gaze fixation, eye blinking, and action-selection [2]. While gaze fixation and eye blinking often incur errors due to unintentional selections, action-selection typically relies on a separate external trigger, which are mostly headset-specific, despite the fact that VR headsets have limited interaction modalities. This paper presents DualGaze, a novel interaction method that makes sole use of gaze to address the Midas Touch problem for gaze mediated VR interaction. It can be readily employed in standard VR menu without the need of having any external triggers. DualGaze is designed in such a way that when the user gazes at a selectable UI element, a confirmation flag would pop up right next to the UI element for the user to willfully look at to confirm the selection; see the left column in Figure 1 for an illustration of the DualGaze interaction procedure. Instead of arbitrarily positioning the confirmation flag, we strategically adapt its location to the user’s gaze trajectory, i.e., we put it at a location that user’s gaze just passed through right before entering the UI element’s boundary. Hence, to confirm a selection, the user needs to consciously avert their eyes back to the flag. In this way, the chance of unintended or accidental gaze at the confirmation flag is reduced, especially when one gazes at a UI element but has no intention of selecting it. Compared to the popularly-employed gaze fixation method (see the right column in Figure 1), DualGaze has higher accuracy in terms of avoiding the Midas touch problem. In addition, the increase in accuracy is obtained without sacrificing the interaction responsiveness in terms of selection speed. These results were confirmed by quantitative data collected from a user study, which shows that users of DualGaze can perform simple gaze-typing tasks with significantly better accuracy than gaze fixation. Further analysis shows that towards the end of the tasks, users’ increasing familiarity with DualGaze resulted in DualGaze outperforming the comparative method in terms of selection speed. This also suggests that the DualGaze technique is not difficult to master. A concluding survey found most users perceive DualGaze to be their preferred gaze interaction method in scenarios where the selection task at hand is deemed critical and irreversible, such as exiting a game. Figure 1: Two comparative interaction designs for selecting a target with one's gaze in a gaze-mediated VR user interface. Our DualGaze method (left) and the Fixed Gaze method (right). *pallavi003@e.ntu.edu.sg † aswbgoh@e.ntu.edu.sg ‡ cwfu@cse.cuhk.edu.hk § saikit@ust.hk 79 2018 IEEE International Symposium on Mixed and Augmented Reality Adjunct (ISMAR-Adjunct) 978-1-5386-7592-2/18/$31.00 ©2018 IEEE DOI 10.1109/ISMAR-Adjunct.2018.00039 Authorized licensed use limited to: Hong Kong University of Science and Technology. Downloaded on February 19,2022 at 13:38:55 UTC from IEEE Xplore. Restrictions apply.