What is childhood blindness?
As the causes of blindness in children differ from those in adults, different control measures are needed. In low-income countries, high proportions of children are blind due to preventable causes; this requires community-based interventions. In all regions, children with treatable diseases, principally cataract, can have their sight restored. Children’s’ eyes cannot, however, be considered smaller versions of adults’ eyes, and specific expertise and equipment is required. Unlike adults, children require long-term follow-up after surgery to manage complications and prevent amblyopia (‘lazy eyes’). The understanding and involvement of parents is critical. In all regions, children with irreversible visual loss must be assessed for low-vision services, early visual stimulation, rehabilitation or special education, depending on their age and level of residual vision.
1.4 million children are estimated to be blind; 1 million of these live in Asia and 300,000 in Africa. They have a lifetime of blindness ahead, with an estimated 75 million blind-years. 500,000 children become blind each year - nearly one per minute. Many die in childhood from underlying causes like measles, meningitis, rubella, prematurity, genetic diseases and head injuries. Most blind children are either born blind or become blind before their fifth birthday. About 40% are preventable or treatable.
The main causes are:
- corneal scarring in Africa and poorer countries in Asia;
- cataract everywhere;
- glaucoma everywhere;
- retinopathy of prematurity in high- and middle-income countries and some cities in Asia;
- refractive errors everywhere, but particularly in South-East Asia; and low vision, which encompasses visual impairment and blindness from untreatable causes, in all regions.
The main causes of blindness in children change over time. As a consequence of child survival programmes (for example, integrated management of childhood illness), corneal scarring due to measles and vitamin A deficiency is declining in many developing countries, so that the proportion due to cataract is increasing. Retinopathy of prematurity is emerging as an important cause in the middle-income countries of Latin America and Eastern Europe and is likely to become an important cause in Asia over the next decade. The prevalence of refractive errors, particularly myopia, is increasing in school-age children.