Table 3

Prevalence and causes of blindness and visual impairment in the adult population

Country	Year	Study design	Race	Age group	No	Type*	Visual acuity in the better eye	Prevalence	Primary causes
*P = presenting acuity, B = best corrected.
Barbados²⁰	1987–92	Simple random sample	Black	40–84	4303	B	≤20/200	3.0%	Glaucoma, cataract, retinal/choroidal diseases
							≤20/400	1.7%
							<20/60–>20/400	5.9%
Chile²¹	1988	Community based rural	Hispanic	≥;60	664	B	≤20/200	4.4%	Cataract, glaucoma, retinal (not AMD)
Brazil²² Sao Paulo	1986–7	Stratified random sample	Hispanic	≥;65	120	P	≤20/400	6.8%	Cataract, myopic degeneration, glaucoma
Brazil²³ Capinas	1986–7	Community based	Hispanic	≥;50	7452	B	≤20/200	2.8%	74% Cataract was involved
Brazil²⁴ Porto Alegre	1992–4	Community based	Hispanic	All ages	All residents neighbourhood	B	≤20/200	0.1%	Cataract, retinal, diabetic retinopathy
Peru²³ Chimbote	1986–7	Community based	Hispanic	≥;40	12193	B	≤20/200	2.9%	72% Cataract was involved

USA
Framingham, MA²⁵	1973–5	Community based	White	≥;55	2631	B	≤20/200	0.6%	Cataract, ARMD, glaucoma, diabetic retinopathy
				75–84	394			2.0%
National Health and Nutrition Examination^26,²⁷	1974–5	Multistage random sample		25–74		P	≤20/200		Not reported
			Black		250			0.2%
			White		2660			0.4%
Hispanic Health and Nutrition Examination^26,²⁷	1982–4	Multistage random sample		25–74		P	≤20/200		Not reported
			Cuban		396			1.0%
			Mexican		1381			0.9%
			Puerto Rican		513			0.2%
Baltimore, MD²⁸²⁹	1985–8	Stratified random sample	White	≥;40	2913	B	≤20/400	0.5%	ARMD, cataract
							≤20/200	0.9%
							<20/60–>20/200	1.3%	Cataract, glaucoma
			Black		2395		≤20/400	0.9%
							≤20/200	1.5%
							<20/60–>20/200	1.9%
Mud Creek Valley, KY³⁰	1988	Community based	White	≥;40	1136	B	≤20/200	1.1%	Cataract, ARMD, diabetic retinopathy, glaucoma
							<20/60–>20/200	1.5%
Beaver Dam, WI³¹	1987–8	Community based	99%	≥;43	4897	B	≤20/200	0.5%	Not reported
			White				<20/60–>20/200	0.8%
3 communities in MA, CT, IO³²	1990	Community based	94%	≥;71	5335	P	≤20/200	4.7%	Not reported
			White				<20/60–>20/200	14.4%
							<20/40–>20/60	14.1%
Salisbury, MD³³³⁴	1994–5	Community based random sample	White	65–84	1853	B	≤20/400	0.2%	Cataract, ARMD, diabetic retinopathy
							≤20/200	0.5%
							<20/60–>20/200	1.2%
			Black		666		≤20/400	0.8%	Cataract, diabetic retinopathy, glaucoma
							≤20/200	1.7%
							<20/60–>20/200	2.6%
Tucson and Nogales, AZ³⁵³⁶	1997–9	Community based random sample	Hispanic	≥;40	4774	B	≤20/400	0.2%	Cataract, ARMD, diabetic retinopathy
							≤20/200	0.3%
							<20/60–>20/200	0.9%