Onchocerciasis is one of world's major public health problems, afflicting some 20 million people in Africa and Central-America. This disease is characterized by ocular complications, leading often to blindness. Onchocerciasis is a micro-filariasis, caused by Onchocerca volvulus-transferred by blackflies from the genus Simulium. The micro-filaria are produced by the adult worms within nodules. They are released into the dermal tissue of the host. Due to their active mobility they are able to reach even the eyes. There are three different main symptoms of onchocerciasis: nodules; dermal alterations; ocular alterations. The severest manifestations of the disease are complications of the eye. We find all kinds and degrees of conjunctivitis, of Ceratitis, of iridocyclitis, of retinitis and of optic atrophy. In areas heavily afflicted this disease dominates all other causes of eye defects and it s likely to produce agronomic fertile areas alongside of rivers, the breeding places of the vectors.