Table 3 Principal cause of moderate to severe visual impairment (UVA worse than 20/63 to 20/400 or better) and blindness (UVA worse than 20/400) per person considering same cause in both eyes and combinations of distinct causes for each eye

Same cause in both eyes

3 (100.00)

10 (100.00)

54 (81.82)

2 (100.00)

6 (100.00)

18 (62.07)

5 (100.00)

16 (100.00)

72 (75.79)

Cataract

34 (51.51)

14 (48.28)

48 (50.53)

Uncorrected refractive error^a

2 (66.33)

3 (30.00)

10 (15.15)

1 (50.00)

2 (33.33)

3 (60.00)

5 (31.25)

10 (10.53)

Retinal abnormalities^b

2 (20.00)

3 (4.54)

1 (16.66)

3 (18.75)

3 (3.16)

Amblyopia

1 (33.33)

1 (10.00)

2 (33.33)

1 (20.00)

3 (18.75)

Corneal opacity / scar

2 (20.00)

1 (3.45)

2 (12.50)

1 (1.05)

Pterygium

3 (4.54)

3 (3.16)

Glaucoma

1 (3.45)

1 (1.05)

Other causes

2 (20.00)

4 (6.06)

1 (50.00)

1 (16.66)

2 (6.90)

1 (20.00)

3 (18.75)

6 (6.32)

Distinct causes for each eye

12 (18.18)

11 (37.93)

23 (24.21)

Cataract | Retinal abnormalities^b

4 (6.06)

3 (10.34)

7 (7.37)

Cataract | Corneal opacity / scar

3 (4.54)

2 (6.90)

5 (5.26)

Cataract | Posterior capsule opacity

2 (6.90)

2 (2.10)

Cataract | Absent globe

1 (3.45)

1 (1.05)

Cataract | Other causes

4 (6.06)

2 (6.90)

6 (6.32)

Uncorrected refractive error^a | Retinal abnormalities^b

1 (1.51)

1 (1.05)

Retinal abnormalities | Corneal opacity / scar

1 (3.45)

1 (1.05)

Total

3 (100.00)

10 (100.00)

66 (100.00)

2 (100.00)

6 (100.00)

29 (100.00)

5 (100.00)

16 (100.00)

95 (100.00)