What causes blindness in children in africa?

Vit A deficiency,etc: Children in africa can be blinded by vitamin a deficiency, onchocerciasis, sometimes malaria, trachoma, injuries, congenital defects some of which might be corrected in a first world country like cataracts at birth, glaucoma, uveitis and a host of other conditions.

River Blindness: The prior response listed many possible causes of blindness. River blindness (onchocerciasis or robles disease) is caused by a roundworm called onchocerca volvulus. This parasitic infection is the second major cause of infectious blindness in the world.