Smartphone gaming while walking increases visual fatigue compared with standing

Mobile gaming differs from passive smartphone activities such as browsing or texting due to its continuous engagement and limited opportunities for pause. Although gaming while walking is common, little is known about its effects on eyestrain. This study recruited 30 young adults (15 men, 15 women) to examine eyestrain during smartphone gaming across two modes (standing, walking) and two durations (15 and 30 min). Four outcomes were assessed: critical flicker fusion frequency (CFF) reduction, visual fatigue scale (VFS), gaze angle, and viewing distance. Results from three-way ANOVA showed that gaming mode significantly affected all responses (p < 0.01). Walking induced greater CFF reduction (2.8 Hz vs. 1.6 Hz in standing, p < 0.001) and higher VFS (4.5 vs. 3.4, p < 0.001), alongside smaller gaze angles and shorter viewing distances. Prolonged gaming (30 min) further increased eyestrain, evidenced by greater CFF reduction and higher VFS scores. Descriptively, viewing distance showed a trend toward reduction, particularly during walking. Sex differences were significant for gaze angle and viewing distance (p < 0.001), with women exhibiting smaller gaze angles and closer viewing distances, but not for fatigue measures. These findings demonstrate that smartphone gaming while walking exacerbates both objective and subjective visual fatigue, and longer sessions intensify these effects, underscoring the risks of mobile gaming during ambulation.