Leprosy, also known as Hansen's disease, affects millions of people worldwide and is largely confined to the developing world. Although Hansen's disease is disfiguring, crippling, and even blinding in its later stages, it is not commonly lethal but gradually steals sensory input from the digits and the visual pathways. In this article, the epidemiology and pathogenesis of leprosy are reviewed, with an emphasis on ocular involvement, treatment, and prevention.