@article{10.1167/iovs.10-6770,
    author = {Ezelum, Christian and Razavi, Hessom and Sivasubramaniam, Selvaraj and Gilbert, Clare E. and Murthy, Gudlavalleti V. S. and Entekume, Gabriel and Abubakar, Tafida and Nigeria National Blindness and Visual Impairment Study Group},
    title = "{Refractive Error in Nigerian Adults: Prevalence, Type, and Spectacle Coverage}",
    journal = {Investigative Ophthalmology & Visual Science},
    volume = {52},
    number = {8},
    pages = {5449-5456},
    year = {2011},
    month = {07},
    abstract = "{   To provide data on prevalence and types of refractive error and the spectacle-wearing rate among adults in Nigeria and the degree to which the need for distance correction could be met by off-the-shelf spectacles.    Multistage, stratified, cluster random sampling with probability proportional to size was used to identify a nationally representative sample of 15,027 persons aged ≥40 years. Distance vision was measured using a reduced logMAR tumbling-E chart. All participants underwent autorefraction, and those with presenting acuity of \\<6/12 in one or both eyes had their corrected acuity measured and underwent detailed clinical examination to determine the cause.    Included in the survey were 13,599 (89.9\\%) of the 15,122 persons aged ≥40 years who were enumerated. Uncorrected refractive error was responsible for 77.9\\% of mild visual impairment (\\<6/12–6/18), 57.1\\% of moderate visual impairment (\\<6/18–6/60), 11.3\\% of severe visual impairment (\\<6/60–3/60), and 1.4\\% of blindness (\\<3/60). The crude prevalence of myopia (≤0.5 D) and high myopia (≤5.0 D) were 16.2\\% and 2.1\\%, respectively. Spectacles could improve the vision of 1279 (9.4\\%) and 882 (6.5\\%) participants at the 6/12 and 6/18 level, respectively, but only 3.4\\% and 4.4\\% of these individuals wore spectacles to the examination site. Approximately 2,140,000 adults in Nigeria would benefit from spectacles that improved their vision from \\<6/12 to ≥6/12. More than a third of the need could be met by low-cost, off-the-shelf spectacles.    Uncorrected refractive errors are an important cause of visual impairment in Nigeria, and services must be dramatically improved to meet the need.  }",
    issn = {1552-5783},
    doi = {10.1167/iovs.10-6770},
    url = {https://doi.org/10.1167/iovs.10-6770},
    eprint = {https://arvojournals.org/arvo/content\_public/journal/iovs/933462/z7g00811005449.pdf},
}