Dry eye disease and blinking behaviors: A narrative review of methodologies for measuring blink dynamics and inducing blink response

Dry eye disease (DED) is a leading cause of ophthalmology clinical encounters with prevalence ranging from 8.7% to 64% in various populations. Blinking is an endogenous process to refresh the tear film, clear debris and maintain quality vision. Altered blinking behavior is a common feature of DED and is implicated in the pathology of the disease. However, lack of a comprehensive review on the relationship between altered blinking behavior and DED is notable in the literature. Blinking behavior may be an effect of DED due to an unstable tear film sensitizing a motor response or be its cause due to destabilization of the tear film in conditions such as benign essential blepharospasm. In this comprehensive review, we summarize the current models and theories of tear film dynamics and blinking behavior to better understand their connection to DED and introduce contemporary technologies and measurement tools used in the evaluation and induction of blinking behavior. We also describe future directions of research to better understand the relationship between DED and blinking and explore therapies that address the abnormal blinking component of DED.