Identification of a blink frequency threshold for maintaining tear film stability in young adults with dry eye symptoms

To determine the critical blink frequency threshold for maintaining tear film stability in young participants with dry eye symptoms. In this two-phase study, 45 young participants (aged 19-28 years) with dry eye symptoms (Ocular Surface Disease Index, OSDI ≥ 13) underwent spontaneous blink measurements (Phase 1) and controlled blink experiments (Phase 2: spontaneous, 10 blinks/min, and 20 blinks/min). Tear meniscus height (TMH), non-invasive tear break-up time (BUT), bulbar redness (BR), and Standard Patient Evaluation of Eye Dryness (SANDE) scores were obtained and analyzed. Spontaneous blink frequency (27.75 ± 14.43 blinks/min) positively correlated with TMH (r = 0.48, p < 0.01). Reducing blink frequency to 10 blinks/min significantly worsened TMH (p = 0.0002), BUT (p < 0.0001), BR (p < 0.0001), and SANDE scores (p < 0.0001) compared to spontaneous blinking. No differences were found between spontaneous blinking and controlled 20 blinks/min. A blink frequency threshold of ≥ 20 blinks/min is critical for stabilizing tear film in young participants with dry eye symptoms. Interventions targeting blink frequency may mitigate symptoms exacerbated by digital device use.