Analysis of the impact of sleep duration and quality on tear‑film in adults with complementary validation of a mobile healthy‑lifestyle application.

AIMS: This study aimed to investigate the relationship between sleep parameters and tear film hydration assessed by tear meniscus height (TMH), and to evaluate the usability of a mobile application for remote behavioral and physiological data collection.

METHODS

Eighteen healthy adults (mean age 29.6 ± 6.4 years) completed five consecutive days of linked measurements combining objective sleep tracking (using Fitbit Charge 4) and slit-lamp imaging of TMH under standardized conditions. Behavioral data on stress, caffeine intake, and smartphone use were collected via a custom mobile application, whose usability was assessed by the System Usability Scale (SUS).

RESULTS

Ninety valid daily records were analyzed. TMH correlated positively with total sleep time (r=0.31, P=0.0033), REM sleep duration (r=0.28, P=0.0066), and sleep quality (r=0.32, P=0.0024). Each additional 30 min of REM sleep increased TMH by approximately 0.014 mm. Short sleepers (<6 h) showed significantly lower TMH (0.121 mm) than normal sleepers (≥6 h; 0.153 mm; P=0.0023). Stress and evening smartphone use were associated with reduced sleep quality and lower TMH. The mobile application achieved excellent usability (SUS = 87 ± 6).

CONCLUSIONS

Our data indicate that sleep duration and architecture play essential roles in maintaining tear film stability. Behavioral habits that impair sleep continuity may thus directly affect ocular surface physiology. The combined use of wearable sensors and mobile self-reporting represents a practical approach to studying the interaction between sleep and ocular physiology.