Abstract
Purpose :
The study of blinking has been hampered in part by the lack of a gold standard condition for measurement. This study measured blinking in situ in a real-life setting during various reading and non-reading tasks and also examined repeatability.
Methods :
Ten healthy adults (30.7±3.6 years; 4M:6F) completed a randomised cross-over intervention study. Participants wore an eye-tracking headset (Pupil Labs GmbH) during 8 tasks (15 min each): A) conversation, B) reading from printed text, C) laptop screen, D) smart TV at 6 m, E) smartphone, F) smartphone at 50% brightness, G) smartphone (more complex text), H) walking indoors. To determine repeatability, task E was completed twice. Symptoms (Instant Ocular Symptom Survey) were measured before and after each task. Spontaneous blink rate and interblink interval were recorded using the headset. Blink parameters were compared between tasks using repeated measures ANOVA and post hoc comparisons with Bonferroni correction. Ocular symptoms pre- and post-task were compared using the Paired t-test. Repeatability was examined using the Bland & Altman method (Coefficient of Repeatability, CoR).
Results :
Blink rate was reduced during all reading tasks (B to G) compared to conversation (p≤0.003) and walking (p≤0.04). There was no significant difference in blink rate between conversation and walking, nor between any of the reading tasks. There were no significant differences in interblink interval between tasks. Ocular symptoms worsened after reading from a smartphone at reduced brightness (p=0.02), more complex text (p=0.04) and from a distant TV screen (p=0.01). CoR was ±14.5 blinks/min for blink rate and ±22.4 s for interblink interval while reading from a smartphone.
Conclusions :
The wearable eye tracker can reliably measure blink rate and interblink interval in situ. In a real-life setting, blink rate was reduced during reading compared to conversation or walking, irrespective of reading task complexity, working distance or device used.
This is a 2021 ARVO Annual Meeting abstract.