Age-Related Visual Attention and Interaction Performance Across Interface Layouts in EV Charging Applications: An Eye-Tracking Study

This study investigates how different interface layouts affect user interaction efficiency and visual processing mechanisms, with a particular focus on the moderating role of age differences. A total of 40 participants were recruited, including 20 younger adults (aged 22–27) and 20 older adults (aged 52–58), who completed three types of tasks—target localization, status confirmation, and functional operation—across four typical electric vehicle (EV) charging application layouts (L1–L4). Eye-tracking techniques were employed to capture average fixation duration, saccade count, fixation-to-saccade ratio, and gaze heatmaps, while task completion time, accuracy, and subjective preferences were analyzed in parallel. The results show that L1 (Bottom Navigation with Top Functional Area) yielded the best performance in both task efficiency and visual processing, with minimal performance differences across age groups. In contrast, L3 (Bottom Navigation with Two-Level Hierarchical Structure) significantly impaired interaction efficiency and increased cognitive load, particularly for older adults. Eye-tracking metrics aligned closely with behavioral data and user preferences, underscoring the critical role of layout structure in shaping attentional allocation and interaction pathways. These findings highlight the importance of adopting intuitive and flat layout designs to enhance universality and usability in cross-age mobile application interfaces.