Statistical analysis
Only data concerning the right eye of each participant was used for further evaluation. Statistical analysis was performed using IBM SPSS Statistics 25 (IBM Corp., Armonk, NY, USA), R Core Team, and StataCorp (Stata Statistical Software: Release 13. College Station, TX: StataCorp LP). For the comparison between healthy and DED groups under the condition of no mask wear, a significance level was set at Agreement of metric variables was assessed by the use of Bland–Altman diagrams, which allow an evaluation of mean difference (MD) as well as the limits of agreement.[