So we know that sleep and dry eye are closely related.

Sleep position may matter. Sleep quality and sleep deprivation have roles to play. A well-known researcher even once suggested that REM sleep is a direct result of the need for ocular surface lubrication.

But what about actual diagnosed sleep disorders? This study looked at the extent to which sleep disorder and dry eye diagnoses overlapped.

Do Sleep Disorders Positively Correlate with Dry Eye Syndrome? Results of National Claim Data. (Han et al, International Journal of Environmental Research and Public Health, March 2019).

ABSTRACT
Purpose: Dry eye syndrome (DES) is a common disease with an increasing occurrence. Although DES symptoms are considered mild, it can reduce quality of life for individuals. Many studies on DES have been conducted, but these focused on the use of electronic devices. Here, we investigate an association between DES and sleep disorders in the context of emerging health issues.
Methods: Our data came from the National Health Insurance Service (NHIS) National Sample Cohort, which included 44,366 patients and was based on a 1:1 matching method (sleep disorder patients vs. patients without sleep disorders) during 2012⁻2015. Using survival analysis with a Cox proportional hazard model, we identified an association of sleep disorders with DES.
Results: About 16.7% of all patients were diagnosed with DES, and prevalence was higher in patients with sleep disorders (sleep disorders: 19.82%, no sleep disorders: 13.67%). Survival analysis showed that sleep disorders positively correlated with DES diagnosis (Hazard Ratio (HR): 1.320, 95% Confidence Interval (CI): 1.261⁻1.382, p-value < 0.0001). Positive trends were enhanced in males, younger patients, lower economic levels, and with higher severity of comorbid.
Conclusions: Our findings suggest that sleep disorder was positively associated with DES. This correlation can be helpful in effective management of both sleep disorders and DES in South Koreans.