Evaluation of Priority-Dependent Notifications for Smart Glasses Based on Peripheral Visual Cues

Abstract Smart glasses are increasingly commercialized and may replace or at least complement smartphones someday. Common smartphone features, such as notifications, should then also be available for smart glasses. However, notifications are of disruptive character given that even unimportant notifications frequently interrupt users performing a primary task. This often leads to distractions and performance degradation. Thus, we propose a concept for displaying notifications in the peripheral field of view of smart glasses and with different visualizations depending on the priority of the notification. We developed three icon-based notifications representing increasing priority: a transparent green icon continuously becoming more opaque (low priority), a yellow icon moving up and down (medium priority), and a red and yellow flashing icon (high priority). To evaluate the concept, we conducted a study with 24 participants who performed a primary task and should react to notifications at the same time using the Nreal Light smart glasses. The results showed that reaction times for the low-priority notification were significantly higher and it was ranked as the least distracting. The medium- and high-priority notifications did not show a clear difference in noticeability, distraction, or workload. We discuss implications of our results for the perception and visualization of notifications in the peripheral field of view of smart glasses and, more generally, for augmented reality applications.