Table 5.

Principal causes of visual acuity <20/32 in eyes by participant age

	Normal/near normal vision <20/32 to ≥20/63		Vision impairment <20/63 to ≥20/200		Blindness <20/200
Principal cause	50–59 years (n = 393)	>60 years (n = 869)	50–59 years (n = 138)	>60 years (n = 447)	50–59 years (n = 89)	>60 years (n = 257)
Refractive error*	353 (89.8)	616 (70.9)	73 (52.9)	116 (26.0)	4 (4.5)	9 (3.5)
Retinal disorders	14 (3.6)	59 (6.8)	24 (17.4)	95 (21.3)	34 (38.2)	88 (34.2)
Other retinal disorders	11 (2.8)	16 (1.8)	15 (10.9)	46 (10.3)	25 (28.1)	43 (16.7)
Diabetic retinopathy	3 (0.8)	18 (2.1)	9 (0.7)	27 (6.0)	9 (10.1)	18 (7.0)
Macular degeneration	0 (0.0)	25 (2.9)	0 (0.0)	22 (4.9)	0 (0.0)	21 (8.2)
Retinal detachment	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	6 (2.3)
Cataract	8 (2.0)	146 (16.8)	10 (7.2)	184 (41.2)	16 (18.0)	82 (31.9)
Amblyopia	5(1.3)	13 (1.5)	20 (14.5)	16 (3.6)	11 (12.4)	15 (5.8)
Glaucoma	4(1.0)	6 (0.7)	1 (0.7)	9 (2.0)	7 (7.9)	21 (8.2)
Corneal opacity/scar	3 (0.8)	3 (0.3)	0 (0.0)	12 (2.7)	4 (4.5)	16 (6.2)
Absent/disorganized globe	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	8 (9.0)	9 (3.5)
Other optic atrophy	1 (0.3)	0 (0.0)	0 (0.0)	4 (0.9)	4 (4.5)	7 (2.7)
Posterior capsule opacification	0 (0.0)	8 (0.9)	2(1.4)	3 (0.7)	0 (0.0)	0 (0.0)
Other causes	1 (0.3)	4 (0.5)	1 (0.7)	4 (0.9)	1 (1.1)	3(1.2)
Undetermined	4(1.0)	14 (1.6)	7(5.1)	4 (0.9)	0 (0.0)	7 (2.7)

^*Includes only eyes improving to ≥20/32 with subjective refraction.