Microbial keratitis is a potentially blinding corneal infection; the infection may progress rapidly if untreated and result in corneal perforation. The breakdown of the innate ocular defences is known to predispose to corneal infection. We present three cases of microbial keratitis in intensive therapy unit (ITU) staff each of whom had compromised corneal immunity. Anaesthetists and nurses regularly perform high-risk procedures, such as tracheal suctioning, which have been known to cause ocular infections by aerosol inoculation. We suggest that although the absolute risk of infection is low, susceptible individuals may be at increased risk of corneal infection from exposure to potentially pathogenic organisms in such environments. We stress the need for ITU staff, particularly those who wear contact lenses, to wear eye protection when performing procedures likely to cause infected aerosols.