Reflecting on lessons learned during the COVID-19 pandemic, the authors of this paper provide an overview of the lifecycle of viruses and how they can infect, with devastating effect. The sections on adenovirus and herpes simplex virus are particularly relevant to optometrists seeking to utilise therapeutic qualifications in the primary or secondary shared care of these patients. Viruses can contaminate equipment and surfaces during an eye examination. This paper identifies the effectiveness of various disinfectants against viruses.