One of the greatest challenges facing world ophthalmology today remains the unacceptably high prevalence of operable cataract blindness in the developing world. The establishment of national and international cataract programmes, frequently funded and supported by international agencies, has achieved a steady increase in the number of cataract operations performed, but current levels remain too low to tackle the backlog of cataract blind, estimated to be 16–20 million, and to stem the rising world incidence consequent on the aging population.

As understanding grows of the dynamics of the problem of cataract blindness, it is increasingly realised that solutions resting on cataract numbers alone are insufficient, and that strategic planning is needed to effect change across a complex web of interrelated constraints if the goal of a high volume sustainable cataract programme is to be achieved.

Fundamental are questions of quality of surgical outcome and cost. As eloquently illustrated by Pokharel et al in two papers in this issue of …