Reducing inequity of cataract blindness and vision impairment is a global priority, but where is the evidence?

Throughout the world, people who are socially or economically disadvantaged disproportionately experience blindness and vision impairment caused by cataract. Reducing vision loss from cataract and its unequal distribution must be a priority if the WHO's aim of 'universal eye health' is to be realised. To help achieve this, decision-makers and service planners need evidence on which strategies improve access to cataract services among disadvantaged populations, and under what circumstances. Unfortunately, despite many strategies to improve cataract services being implemented in recent decades, evidence of what works, for who and in what circumstances is not readily available. This paper summarises the extent of the evidence on interventions to reduce inequity of vision loss from cataract and makes suggestions for how the evidence base can be strengthened.