Maintaining Tear Film Stability in Dry Eye Requires Frequent Blinking

The frequency of blinking can affect the stability of tear film in those living with dry eye, with the threshold of 20 blinks per minute affecting tear break-up time (BUT) and tear meniscus height (TMH), among other symptoms of dry eye, according to a new study.¹ Mitigating factors like digital device use can help to target blink frequency.

Tear film instability is a primary symptom of dry eye disease, which is a chronic ocular disease defined by either the eyes not making enough tears or the tears not working correctly.² Approximately 16.4 million people in the US are living with dry eye, and the prevalence remains high throughout the world. The use of digital devices could be increasing the prevalence of dry eye, especially in younger individuals, due to the decreased amount of blinking done when looking at digital devices. The association between blink frequency and tear film stability could help to identify when tear film is significantly affected. This study aimed to assess that connection to determine the threshold of blinking to maintain normal levels in the tear film.¹

Participants were recruited for the cross-sectional observational study through internet recruitment and posters advertising the study in hospitals, schools, and communities. Participants needed to be aged 14 to 35 years, have a diagnosis of dry eye, and have no significant damage to the cornea. Those who had a history of eye surgery or trauma, had a history of ocular medication use, had autoimmune diseases or any other ocular disease, used medications that could affect blinking, or were pregnant were excluded from the study.

Eye-tracking glasses were used to measure blink frequency, and demographic questionnaires were given to all participants. The questionnaires included a baseline data collection of dry eye symptoms and how blink frequencies subjectively affected the patient. The effects of spontaneous blinking, 10 blinks per minute, and 20 blinks per minute were all tested in the patients. BUT, TMH, tear film lipid layer, meibomian dropout score, and bulbar redness (BR) were all measured.

There were 45 individuals included in this study, with all eyes included in the analysis. The mean (SD) age of the cohort was 23.64 (2.27) years. The participants had a mean blink rate of 27.75 (14.43) blinks per minute, with the mean interval between blinks being 3.04 (2.64) seconds. Researchers found that there was a connection between higher blink rate and higher TMH but no correlation between blink rate and BUT.

Those in the spontaneous blinking group had significantly higher TMH compared with those who blinked 10 times per minute. However, TMH was significantly higher in the spontaneous and 20-blink groups compared with the 10-blink group in the patient’s dominant eye.

The first BUT was significantly higher in both the spontaneous (12.60 [0.17]) and 20-blink groups (9.55 [5.78]) compared with the 10-blink group (6.90 [3.58]) in both eyes. There were no differences between the spontaneous and 20-blink groups when it came to the dominant eyes, but both had significantly higher BUT than the 10-blink group. Average BUT was significantly higher in the spontaneous (14.97 [6.12]) and 20-blink (12.07 [5.76]) groups compared with the 10-blink group (8.94 [3.85]) in both eyes.

BR was significantly lower in the spontaneous (0.79 [0.41]) and 20-blink (0.97 [0.04]) groups compared with the 10-blink group (1.17 [0.53]). Both frequency (29.27 [16.73] and 38.73 [19.30]) and severity (28.29 [17.11] and 37.93 [18.58]) scores for dry eye symptoms were lower in the spontaneous and 20-blink groups, respectively, when compared with the 10-blink-per-minute group (55.04 [18.51] and 55.36 [22.29], respectively).

Patients with severe symptoms of dry eye had higher TMH, first BUT, average BUT, and BR in the spontaneous group compared with the 10 and 20 blinks per minute groups.

There were some limitations to this study. The generalizability of the findings is limited due to the small sample size. Improved dry eye symptoms and increased blink frequency did not show a significant correlation in the questionnaires given to the patients. Conscious control of blinking could be possible due to all patients being aware of their blinking being monitored. All participants were evaluated in a lab, which may not make the findings generalizable to real-world situations.

“The results show that increasing blink frequency significantly improves tear meniscus height and tear film stability, highlighting the role of blinking in maintaining tear film function and alleviating dry eye symptoms,” the authors wrote. “Moderately increasing blink frequency may be an effective strategy for improving tear film health in individuals with dry eye symptoms, supporting the development of eye protection strategies.”

References

1. Chai Y, Cheng M, Liu X, et al. Identification of a blink frequency threshold for maintaining tear film stability in young adults with dry eye symptoms. Sci Rep. 2025;15:42321. doi:10.1038/s41598-025-26424-z

2. Dry eye. National Eye Institute. Updated August 6, 2025. Accessed December 2, 2025. https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/dry-eye