Demodex is one of the most common, but often overlooked, causes of blepharitis and ocular surface inflammation, being associated with between 29% and 74% of all cases of blepharitis. This article will review demodex, its prevalence, its diagnosis and its treatment. 

This article introduces demodex, including its natural history and its association with case of ocular surface inflammation and blepharitis. The best diagnostic practices, when to inform patients and consider treatment is also discussed. The evidence behind current treatments, and the safety and efficacy of available products will also be outlined.