Every minute, somewhere in the world, a child goes blind according to the World Health Organisation. Three in five poor children who go blind are likely to die within two years of losing their sight - yet half of cases of childhood blindness are avoidable. Sub-Saharan Africa is the region with the highest prevalence of blindness in the world - 1.24 per 1,000 children, compared to 0.8 in India and 0.3 in Europe.