Loiasis is a parasitic disease caused by the filarial worm Loa loa, commonly known as the African eye worm. It is transmitted to humans through the bite of infected mango flies, which are prevalent in certain regions of West and Central Africa. The adult worms can live in the human body for years, often migrating under the skin and sometimes across the eye. Symptoms of loiasis may include swelling, itching, and pain in the affected areas. In some cases, the worm can be seen moving across the eye, causing discomfort. Diagnosis is typically made through blood tests, and treatment usually involves medication to eliminate the parasites.