Epidemics of a bilateral symmetrical optic neuropathy have occurred at various times in the previous century and earlier. The outbreaks have occurred in the context of nutrtional deficiency but a precise cause has yet to be established. A particularly high profile outbreak occurred in Cuba in 1989 but was short-lived while an epidemic in Tanzania which was reported first at about the same time is continuing. Evidence will be presented that the condition occurs in Somalia although there are no prevalence data. The condition is also found in the Gambia but the prevalence was found to be considerably lower than in Tanzania. Finally results will be presented of a cohort of 300 acute cases recruited in Dar es Salaam, Tanzania who were treated with multivitamins. Ethical permission was not given for a placebo group but the results suggest considerable improvement in visual outcome. The incidence of cases developing peripheral neuropathy and hearing loss in this cohort will also be presented and discussed.