Causes of blindness from some recent population based studies of all age groups in developing countries
| Country | Percentage prevalence of blindness | |||
|---|---|---|---|---|
| Cataract | Refractive error | Trachoma | Onchocerciasis | |
| China28 | 0.18 | NA | 0.05 | nil |
| Lebanon29 | 0.25 | 0.08 | nil | nil |
| South Africa30 | 0.59 | NA | nil | nil |
| India14 | 0.61 | 0.20 | nil | nil |
| Mali25 | 1.17 | nil | 0.21 | nil |
| Central African Republic26 | 0.36 | nil | 0.10 | 1.61 |
| Other corneal opacity | Glaucoma | Others | Total | |
| China28 | 0.07 | 0.04 | 0.10 | 0.43 |
| Lebanon29 | 0.05 | 0.02 | 0.20 | 0.60 |
| South Africa30 | 0.02 | 0.23 | 0.16 | 1.00 |
| India14 | 0.12 | 0.12 | 0.29 | 1.34 |
| Mali25 | 0.12 | 0.14 | 0.06 | 1.70 |
| Central African Republic26 | nil | 0.05 | 0.08 | 2.20 |
↵Blindness defined as visual acuity <3/60 in the better eye. Best corrected visual acuity used to define blindness in studies from China and South Africa, and presenting visual acuity used in the other studies.
↵Refractive error blindness includes aphakia. The study from India also includes refractive error related amblyopia.
↵Other corneal opacities are mainly vitamin A deficiency, infectious keratitis, and use of harmful traditional eye medicines.
NA is not applicable as these two studies used best corrected visual acuity to define blindness.