Prevalence and causes of blindness and low vision
| Country (reference) | Prevalence of blindness and/or [low vision] | Age group examined | Proportion of bilateral blindness [low vision] due to: | ||||
|---|---|---|---|---|---|---|---|
| Cataract | Trachoma | Glaucoma | Cornea | ||||
| Benin (1) | 0.6 (0.4–0.9) [2.6 (2.1–3.1)] |
All | 54 [63] | [4] | 15 [3.4] | 11 | |
| Cameroon (2) | 1.2 | 6+ | 55 | 7.4 | 12 | ||
| Central African Republic (3) | 2.2 (1.83–2.57) [3.0 (2.53–3.38)] |
All | 16.4 [54] | 4.5 [1.7] | 2.2 [0] | ||
| Congo (4) | 0.3 [2.1] | All | 81 [80] | 9 [3.4] | |||
| Ethiopia (5) | 1.83 | 7+ years | |||||
| Ethiopia (6) | 0.85 (0.63–1.07) [1.7 (1.4–1.9)] |
All | 47.7 | 20.6 | 9.5 | ||
| Ethiopia (7) | 1.9 (1.1–2.9) | All | 47 | 26 | |||
| The Gambia (8) | 0.7 [1.4] | All | 45 [57] | 17 | 2 | 20 [13] | |
| Ghana (9) | 1.7 (1.1–2.5) | 30+ years | 62.5 [51.5] | 0 [0] | 0 [0] | 8.2 [10.3] | |
| Kenya (10) | 0.7 [2.5] | All | 38 (39) | 18.7 (12.9) | 8.6 | ||
| Malawi (11) | 1.27 (0.76–1.96) [2.0] | 6+ years | 40 [58] | 15 [3.2] | 30 [6.5] | ||
| Mali (12) | 1.7 [1.7] | All | 68.7 [63.3] | 12.1 | 8.1 | ||
| Niger (13) | 1.67 | All | 59 | 2.4 | |||
| Nigeria (14) | 11.8 [16.1] | All | |||||
| Nigeria (15) | 0.33 (0.06–0.6) [1.08] | All | 70.6 [82] | 17.6 [4.4] | |||
| Nigeria (16) | 0.9 (0.84–0.96) | All | 48 | 11 | |||
| South Africa (17) | 1.0 (0.7–1.2) [1.4 (1.1–1.7)] |
All | 59 [68.2] | 23 [4.7] | |||
| South Africa (18) | 0.57 (0.46–0.68) | All | 55 | 10 | 6 | ||
| Sudan (19) | 6.4 [4.7] | All | |||||
| Tanzania (20) | 1.26 (0.8–1.89) [1.04] | 7+ years | 22 [31] | 26 [15.8] | 17.4 | 17.4 [15.9] | |
| Togo (21) | 0.82 | All | 39–70 | 0.9–10.7 | 3.6–7.6 | ||
| Zambia (22) | 3.6 [12.1] | 6+ years | [54] | [24] | |||
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↵Blindness is defined as <3/60 by all surveys except Sudan, where blindness is <6/60. Low vision is <6/18, ⩾3/60 except for the following: Sudan <6/18, ⩾6/60; Benin <6/60, ⩾3/60 (95% confidence intervals, when provided).
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↵These might have included some blindness from trachoma.
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↵Causes of blindness include blindness and low vision combined.
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↵Survey was in an onchocerciasis endemic region where onchocerciasis accounted for 73% of blindness.
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↵This includes phthisis bulbi.
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↵At the time of this survey this region was known for vitamin A deficiency.
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↵Survey in an onchocerciasis endemic region.
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↵Survey covered four separate regions in which the causes of blindness varied. Prevalence is for all regions combined.
