Results
Eleven ENT surgeons took part in the study. All were comfortable and experienced in using the operating microscope. Grade of surgeon ranged from ST3 registrar to senior consultant. Inter-pupillary distance ranged from 58mm to 75mm (median 64mm). Four of the 11 surgeons wore prescription glasses for operating, and as such could not be tested at PPE level B (FFP3 mask with no eye protection or glasses). A total of 51 measures of eye-microscope distance and target scores were collected covering all of the defined PPE categories (A to E).