Blink Rate Measured In Situ Decreases While Reading From Printed Text Or Digital Devices Regardless Of Task Duration Complexity

Purpose: To compare blinking measured in situ during various tasks and examine relationships with ocular surface symptoms. Day-to-day repeatability of blink rate and interblink interval was assessed. Methods: Twenty-four students (28.6+/-6.3 years; 8M:16F) completed six reading tasks (printed text, laptop, TV, smartphone, smartphone at 50% brightness, smartphone with complex text), and two non-reading tasks (conversation, walking) in a randomised cross-over study. Ocular surface symptoms and clinical signs were assessed. Blink rate and interblink interval were measured using a wearable eye tracking headset. Blink parameters were compared across tasks and time (linear mixed model and post hoc comparisons with Bonferroni correction). Associations between blinking, symptoms, ocular surface, and clinical signs were assessed (Spearman correlation). The smartphone reading task was completed twice to determine coefficient of repeatability. Results: Blink rate was lower (mean 10.7+/-9.7 blinks/min) and interblink interval longer (mean 9.6+/-8.7s) during all reading tasks compared to conversation (mean 32.4+/-12.4 blinks/min; 1.5+/-0.6s) and walking (mean 31.3+/-15.5 blinks/min; 1.9+/-1.3s) (p

Competing Interest Statement
The authors have declared no competing interest.

Funding Statement
This research did not receive specific funding from agencies in the public, commercial, or not-for-profit sectors. The first author, NC received a UNSW Tuition Fee Remission Postgraduate Research Scholarship and the Australian Government Research Training Program Thesis Completion Scholarship. The research was also supported by the Dorothy Carlborg Research Grant from the Cornea and Contact Lens Society of Australia, and the UNSW Faculty of Science Research Infrastructure Scheme. The funding sources have no involvement in the study design, conduct of the research, collection, analysis and interpretation of data, writing of the report, preparation of the article or in the decision to submit the article for publication.

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