Anyone who has spent time in Asia or Africa can invariably recall a vivid image of a blind beggar, sometimes an elderly person but frequently a child with opaque corneas, haunting the bazaars and marketplaces of cities and villages. The spectre is so common that it almost passes unnoticed, but these individuals who are bilaterally blind represent only a small fraction of the millions who suffer monocular blindness as a result of corneal trauma and subsequent microbial keratitis.

With the global figure of blindness rapidly approaching 40 million, attention naturally is focused on cataract, which is responsible for 50% or more of all visual disability, and trachoma which is still an enormous public health problem affecting 500 million people worldwide and responsible for 25% of all bilaterally blind individuals.1 Xerophthalmia, onchocerciasis, and glaucoma account for several millions more of the 85% of the world’s blind individuals who live in developing countries in Asia and Africa.2

While corneal blindness in the developing world has traditionally been attributed to trachoma, xerophthalmia, …