Smartphone gaming induces dry eye symptoms and reduces blinking in school-aged children

PURPOSE: Smartphone use by children is rising rapidly, but its ocular surface impact is unknown. This study examined the effect of smartphone use on blinking, symptoms, and tear function in children. METHODS: In a prospective intervention study, 36 children aged 6–15 years played games on a smartphone continuously for one hour. Symptoms (SANDE, JOSS/IOSS, NRS) and tear film (lipid layer thickness, tear secretion, stability) were assessed before and after gaming. Blink rate and interblink interval were measured in situ with a wearable eye-tracking headset before (during conversation) and continuously throughout gaming. Paired t-tests, repeated-measures ANOVA with Bonferroni corrections, and Pearson correlations were used (alpha = 0.05). RESULTS: Symptoms worsened after one hour (SANDE +8.2 units, p = 0.01; JOSS +1.3 units, p < 0.001; NRS-average +6.3 units, p = 0.03; NRS-comfort +7.6 units, p = 0.04; NRS-tiredness +10.1 units, p = 0.01), while tear film metrics remained unchanged. Blink rate decreased from 20.8 to 8.9 blinks/min (p < 0.001) and interblink interval increased from 2.9 s to 8.7 s (p = 0.002) within the first minute of gaming versus baseline conversation, and remained at these altered levels throughout the hour. CONCLUSIONS: One hour of smartphone use in children induces dry eye symptoms and immediate, sustained slowing of blinking without detectable tear film change. Given ubiquitous smartphone use, future work should examine whether effects persist or worsen over longer durations, potentially causing cumulative ocular surface damage.