What is the global burden of visual impairment?

Table 2 Data on contribution of uncorrected refractive error to blindness and less severe visual impairment in qualifying surveys.

GBD sub-region	Country	Year of publica-tion of study [Ref]	Number of participants in survey	Partici-pation rate of those sampled (%)	Age group (years)	Blindness* rate (%)	Percent of blindness due to un-corrected refractive error	Less severe visual impairment† rate (%)	Percent of less severe visual impairment due to uncorrected refractive error	Types of refractive error causing visual impairment‡
AFRO E	Ethiopia	1997 [10]	7423	90	All ages	0.85	8.0	1.68	28.8	Unspecified refractive error, aphakia
EMRO B	Lebanon	1997 [11]	10148	90	All ages	0.60	12.6	3.90	50.0	Myopia, hyperopia, aphakia
EURO B1	Turkey	1996 [12]	7497	87	All ages	0.40	12.0	1.50	29.0	Unspecified refractive error, aphakia
SEARO B	Malaysia	2002 [13]	18027	69	All ages	0.29	10.4	2.44	56.1	Unspecified refractive error, aphakia
SEARO D	India	2001 [14] 2002 [15]	10293	87	All ages	1.34	14.9	8.59	45.0	Myopia, hyperopia, aphakia, pseudo-phakia, refractive error related amblyopia
SEARO D	Pakistan§	1998 [16]	1156	90	All ages	2.08	16.7	6.92	55.0	Unspecified refractive error
SEARO D	Pakistan	2005 [17]	1106	94	40 or more	1.90	14.3	8.05	29.2	Unspecified refractive error, aphakia
WPRO A	Australia	2001 [18]	4744	86	40 or more	0.16	0.0	1.56	37.6	Myopia, hyperopia
WPRO B1	China	1999 [19]	5342	83	50 or more	2.67	12.4	NA	NA	Unspecified refractive error

*Blindness defined as presenting visual acuity less than 3/60; these studies, with two exceptions, did not include visual field loss criteria for blindness.
†Less severe visual impairment defined as presenting visual acuity less than 6/18 to 3/60.
‡Visual impairment defined as presenting visual acuity less than 6/18, which includes both blindness and less severe visual impairment.
§This study was on Afghan refugees in Pakistan; this would reflect more the visual impairment in Afghanistan, which is also in the SEARO D sub-region according to the GBD classification.
NA stands for not available.

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