Introduction
dry eye disease, non-dry eye
DRY EYE
During the global COVID-19 pandemic, several publications have reported an increase in the incidence of dry eye disease (DED), and an association with the increased use of face masks and respirators has been considered [During the first waves of the pandemic, the scarcity of certified personal protective equipment resulted in the use of a wide variety of materials and manufacturing techniques to produce masks for the general population. As the availability of three-ply nonwoven fabric surgical masks and FFP2/KN95 respirators has improved, these “medical” masks are widely used, and some European countries, such as Germany, specifically require their use in settings such as public transport or hospitals.An association of the use of face masks with symptoms of dry eye has been reported. Recently, Krolo et al. reported significantly increased ocular surface disease index (OSDI) scores with a mask-wearing time of 3 h in non-dry eye patients [