Healthcare professionals aged between 18 and 40 attending the same workplace environment and wearing surgical facial masks for at least 8 h per day from the beginning of the pandemic (March 2020, since the facial mask use had become mandatory) were included in the study as group 1. Healthy subjects aged between 18 and 40 who had no ocular disease history or ocular complaints and wore facial masks less than 2 h per day or 16 h per week were included in group 2 for comparative analyses. Subjects using glasses or contact lenses, using a different facial mask other than the surgical masks, subjects with active ocular allergy findings (papillary conjunctivitis), corneal vascularization, current or previous history of herpetic keratitis, severe meibomian gland dysfunction, pregnancy, retinal problems or glaucoma, history of ocular surgery, and any systemic or ocular medical treatment, including artificial tear drops, were excluded from the study.