In situ blinking is not affected by age or habitual digital device use, according to a study published in the British Journal of Ophthalmology. Faster blink rate and shorter interblink interval are associated with increased tear volume, but do not affect ocular symptoms.
Researchers enrolled 45 school-aged children (56% girls; age range, 6-15 years) in a cross-sectional, observational study. All participants completed various subjective dry eye assessment questionnaires and reported time spent using digital devices. Patients underwent tear film lipid layer assessment, biomicroscopy, meibography imaging, and meibomian gland expressibility assessment.
A child-sized, monocular, wearable eye-tracking headset assessed blinking during 10 minutes of conversation and recorded blink activity using eye-tracking software. The blink rate and interblink interval were determined from the timestamp of blink onset and offset and a manual count validated these measurements.
The pupil blink detection software agreed with the manual count, confirming the software’s validity for blink tracking.
According to the report, the mean blink rate and interblink intervals were 20.5±10.5 blinks per minute and 2.9±1.9 seconds, respectively. No difference was noted between automated and manual blink rate (P =.78) and no association was observed between blinking and digital device use, age, or sex.
Increased tear volume was associated with a faster blink rate (r=0.46; P =.001) and a shorter interblink interval (r=−0.36; P =.02), and older age was associated with improved tear volume (r=0.37, P =.01) and stability (r=0.38, P =.01).
“Blinking in children is not affected by age, or habitual digital device use and is similar to that previously reported in adults,” according to the researchers. “Faster blink rate and shorter interblink interval were associated with greater tear volume but not symptoms.”
Study limitations include potential geographic bias and reliance on self-reported data.
Chidi-Egboka NC, Jalbert I, Wagner P, Golebiowski B. Blinking and normal ocular surface in school-aged children and the effects of age and screen time. Br J Ophthalmol. Published online August 24, 2022. doi:10.1136/bjo-2022-321645