Purpose: We investigated the the effect of wearing a loose mask on tear-film break-up time using cross-sectional and experimental methods. Methods: This was a comparative analysis of non-invasive tear-film break-up time (NIBUT) after wearing no mask, loose mask, and tight mask for 10 minutes each in 60 eyes with or without dry eye syndrome. NIBUT measurements were performed using a keratograph. Results: The NIBUT values were 7.53 ± 0.83 seconds, 6.19 ± 0.78 seconds, and 7.36 ± 0.68 seconds for the no mask, loose mask, and tight mask groups, respectively. There was no significant difference between the no mask and tight mask groups (ρ-value = 0.517), but the loose mask group had a significantly reduced NIBUT compared with the other groups (ρ-value = 0.013 and 0.022, respectively). Conclusions Wearing a loose mask reduced the tear-film break-up time regardless of the presence or absence of dry eyes and may cause or worsen dry eye symptoms.

Purpose: To report two cases of cataract that progressed after COVID-19 mRNA vaccination.Case summary: Two patients visited our clinic with decreased visual acuity in the left eye that began after mRNA vaccine. A 40-year-old man visited our hospital with decreased visual acuity in the left eye that developed 1 week after injection of the second dose of mRNA-1273 (Moderna ® ,Cambridge, UK). A 40-year-old woman visited our clinic with decreased visual acuity in the left eye that occurred on day 46 after the injection of the third dose of BNT162b2 (Pfizer ® , New York, NY, USA). Neither case had any relevant ophthalmic history, and there was no clear optic neuropathy or retinopathy on fundus examination. After phacoemulsification and intraocular lens implantation, the best-corrected visual acuity improved, and intraocular pressure has remained stable. Conclusions The possibility of cataract development or progression after COVID-19 mRNA vaccine injection should be considered.