OBJECTIVE To investigate the safety of face masks worn by patients during intravitreal injections. METHODS A prospective, qualitative, interventional study performed in a tertiary university hospital. Healthy volunteers were asked to wear three different professional surgical face masks while air leaks around the eyes were monitored. Three types of masks were investigated as follows: 1) surgical face mask with four tying strips, 2) surgical face mask with elastic ear loops and 3) 2200 N95 tuberculosis particulate face mask. For each session the periocular area was inspected for air leak during normal respiration, speech, and deep respiration. Detection of air leak was performed using the following two professional thermal cameras: FLIR A310-thermal camera and EyeCGas 2.0-super sensitive infrared camera used for detection of minute fugitive emissions of industrial gases. RESULTS Ten healthy volunteers were enrolled in this study. The experiment was repeated 45 times for each camera; 3 times for each of 3 mask types, on 5 volunteers, for a total of 90 trials. Air jets were detected originating from the superior edges of the masks radiating toward the eyes in 81% (73/90) of cases in total; 71% (32/45) with the FLIR camera and 91% (41/45) with the OPGAL camera. Air leaks were detected with all investigated mask types. CONCLUSIONS Patients wearing face masks during intravitreal injections may be at a higher risk of endophthalmitis. Until further data are available, we recommend verifying proper face mask fitting and either taping the upper edges of the face masks with a medical adhesive tape or using an adhesive surgical drape around the injected eye.