About 40 million people in Nigeria, a quarter of the country's population, are at risk of contracting onchocerciasis, also known as river blindness, a disease caused by infection with the parasitic worm.

The illness, which can be picked up from just fetching water from the river, is the second most common cause of blindness in the world after trachoma.

Al Jazeera's Mohammed Adow reports from one of the many communities crippled by onchocerciasis.

Source: Al Jazeera