Table 3. Principal causes of blindness and visual impairment by person.

Primary cause of VI (VA<6/18)	Blindness		Severe VI		Moderate VI
	n	%	n	%	n	%
1. Uncorrected refractive error	0	0.0	4	4.1	131	15.9
2. Aphakia uncorrected	0	0.0	0	0.0	2	0.2
3. Cataract untreated	133	58.6	116	70.1	688	68.2
4. Cataract surgical complication	6	5.3	2	1.1	34	4.6
5. Pterygium	4	0.7	2	0.9	4	0.2
6. Corneal opacity	8	3.5	3	1.4	1	0.3
7. Pthisis	3	0.7	0	0.0	0	0.0
8. Myopic Degeneration	1	0.4	0	0.0	1	0.3
9. Glaucoma	14	6.6	6	4.4	14	2.0
10. Diabetic Retinopathy	9	10.4	13	8.4	33	5.4
11. ARMD	0	0	1	0.8	4	0.6
12. Other Posterior Segment Disease	18	8.4	7	7.0	11	1.5
13. All Other Globe/CNS Abnormalities	9	5.4	2	1.7	6	0.8
Total	205	100.0	156	100.0	929	100.0
Intervention Category	Blindness		Severe VI		Moderate VI
	n	%	n	%	n	%
A. Treatable (1,2,3)	133	58.6	120	74.2	821	84.3
B. Preventable (PHC/PEC Services) (5,6,7,8)	16	5.3	5	2.3	6	0.8
C. Preventable (Ophthalmic Services) (4,9,10)	29	22.3	21	13.9	81	12.0
D. Avoidable (A+B+C)	178	86.2	146	90.4	908	97.1
E. Posterior Segment Causes (8,9,10,11,12)	42	25.8	27	20.6	63	9.8

VI, visual impairment; VA, visual acuity; ARMD, age-related macula degeneration; CNS, central nervous system; PHC, primary health care; PEC, primary eye care