Fig. 2From: Risk factors for open-angle glaucoma in Nigeria: results from the Nigeria National Blindness and Visual Impairment SurveyGeographical origins of ethnic groups and their open-angle glaucoma prevalence. Adapted from Map of the ethno-linguistic groups of Nigeria. Source: University of Texas Libraries; obtained from https://commons.wikimedia.org/wiki/File:Nigeria_linguistic_1979.jpg Back to article page