Comfortably Going Blank: Optimizing the Position of Optical Combiners for Monocular Head-Worn Displays During Inactivity

Smart glasses, such as the Epson Moverio and Tooz DevKit, are often designed so that the display is near the ear and an optical combiner is positioned to reflect the display into the user’s eye. When the display is off, this combiner can still be seen as an out-of-focus edge or discoloration in the lens. Therefore, positioning the combiner to be unobtrusive when the display is off is essential to the users’ comfort. We simulated monocular, right-eyed displays with optical combiners' centralmost edges offset by different angles from the primary position of gaze (PPOG) to evaluate participants’ perceived comfort. Results suggest that to improve user's comfort, the edges of optical combiner should be beyond 20.2° towards the nose or 8.7° towards the ear from the PPOG horizontally.