Prevalence of visual impairment in Nirmal district in Telanagana, India as reported in various studies
| Year | Sample size | Moderate visual impairment (presenting visual acuity worse than 6/18–6/60) | Severe visual impairment (presenting visual acuity worse than 6/60–3/60) | Blindness (presenting visual acuity worse than 3/60) | Total visual impairment (presenting visual acuity worse than 6/18) | |
| n | % | % | % | % | ||
| ≥40 years | ||||||
| APEDS19 20 | 1997–1998 | 840 | 28.5 | 1.8 | 5.0 | 35.2 |
| RAVI 14 | 2014 | 2974 | 10.4 | 1.5 | 1.9 | 13.7 |
| RAVI | 2022 | 2392 | 8.8 | 0.4 | 0.6 | 9.7 |
| ≥50 years | ||||||
| APEDS 19 20 | 1997–1998 | 521 | 40.3 | 2.9 | 7.5 | 50.7 |
| RACSS 27 | 2006–2007 | 2160 | 13.6 | 4.8 | 3.2 | 21.6 |
| RAVI 14 | 2014 | 1550 | 16.6 | 2.3 | 3.0 | 21.9 |
| RAVI | 2022 | 1491 | 13.4 | 1.1 | 1.7 | 16.2 |
APEDS, Andhra Pradesh Eye Disease Study; RACSS, Rapid Assessment of Cataract Surgical Services; RAVI, Rapid Assessment of Visual Impairment.