Abstract
Purpose :
Smartphone use by children is increasing rapidly, but the ocular impacts are unknown. This study examined the effect of 1 hour of smartphone use on symptoms, tear film and blinking in children.
Methods :
Forty-five children aged 6–15 years (mean 10.1±2.6 years; 20M:25F) with healthy eyes and no binocular vision problems completed this prospective study. Children played games on a smartphone continuously for 1 hour and were masked to the study purpose. Symptoms were measured before and after using Symptoms Assessment in Dry Eye (SANDE), Instant Ocular Symptoms Survey (IOSS), Numerical Rating Scale (NRS). Tear film lipid layer thickness (LLT) (LipiView® interferometer.), tear meniscus height (TMH) and non-invasive tear break-up time (NIBUT) (Oculus® Keratograph 5) were assessed at the same timepoints. Spontaneous blink rate (blinks per minute) and interblink interval (time of full eyelid opening, seconds) were assessed in situ, at baseline (during conversation) and throughout the 1 hour of smartphone gaming, using a novel wearable eye tracking headset (Pupil Labs GmbH). Blink rate and interblink interval were compared between baseline and at 10 minutes intervals during smartphone use with repeated measures ANOVA and post hoc comparisons with Dunnett’s test and Bonferroni correction. Associations were examined using Pearson correlation.
Results :
Ocular surface symptoms increased following 1 hour of smartphone use (SANDE +7.3 units, p=0.01; NRS overall +6.6, p=0.01; NRS comfort +8.5, p=0.01; NRS tiredness +11.2, p=0.004; IOSS +1.3, p<0.001), but tear film (LLT, TMH, and NIBUT) remained unchanged. Mean group blink rate reduced from 20.7±9.9 blinks/min during conversation to 7.4±5.2 blinks/min within 10 minutes of smartphone use (p<0.001), and interblink interval increased (3.1 s vs 8.4 s; p<0.001). Blink rate and interblink interval remained unchanged throughout 1 hour of smartphone use. There were no significant associations between changes in blink rate, interblink interval and symptoms.
Conclusions :
Blinking in children can be successfully assessed in situ using a wearable eye tracking device. Smartphone use quickly resulted in dry eye symptoms, slowed the blink rate to one-third, with much longer open eye periods between blinks. In the short-term, this was not accompanied by disturbances to the tear film.
This is a 2021 ARVO Annual Meeting abstract.