Dry eye disease is a widespread ocular surface condition (prevalence 5.5-33.7%) that has been previously linked to systemic diseases, such as Sjogren, rheumatoid arthritis and more recently possibly also depression, in small population-based studies. The authors’ aim was to investigate this association in a large, adult, inclusive study and for this reason conducted a retrospective, case-control review of all patients over 18 years, that were seen in the outpatient setting of a large university hospital between 2008 and 2013. They used diagnostic codes (ICD-9) for dry eyes, depression, anxiety and rheumatoid arthritis (as a validating disease), and utilised these codes to calculate odds ratios separately for dry eyes and each of the other diseases. They applied logistic regression models to estimate associated odds ratios, which was each adjusted for age and sex, along with 95% confidence intervals. A total of 460,611 patients were included, with 7207 patients with dry eyes, 20,004 with anxiety and 30,100 with depression. Seventy-six patients were excluded because age could not be determined. The odds ratios between dry eyes and anxiety were 2.8 (95% CI 2.6, 3.0), and between dry eyes and depression 2.9 (95% CI 2.7, 3.1). The odds ratios between rheumatoid arthritis and dry eyes was 3.2 (95% CI 2.8, 3.7). The authors also found a greater association of dry eyes and rheumatoid arthritis in the younger age group. These findings are statistically significant and confirm the association between dry eyes and anxiety / depression in (so far) the largest population cohort. This may have implications for the healthcare providers to be aware and perhaps initiate screening for these comorbidities in dry eye patients. The authors argue that the major strength of their study is its large and diverse size, which makes the results more generalisable. They also point out the limitations imposed by its retrospective nature, which did not allow any conclusions about causality, and the possibility of confounding factors, such as possible medications that patients were using to treat depression (tricyclic antidepressants being a risk factor for dry eyes due to their anticholinergic effect). The authors recommend further studies assessing the above, as well as the effects of treated depression on the management of dry eyes.