Table 3.

Aetiological classification based on time of onset of visual loss of severe visual impairment and blindness in 650 children examined in 13 schools for the blind in Delhi

Aetiology	No	No	%	%
Hereditary factors	87		13.4
Autosomal recessive		38		5.8
Autosomal dominant		10		1.5
Others		39		6.0
Intrauterine factors	6		0.9
Rubella		3		0.5
Others		3		0.5
Perinatal factors	8		1.2
ROP		3		0.5
Neonatal meningitis		3		0.5
Others		2		0.3
Childhood factors	182		28.0
Vitamin A deficiency		133		20.5
Meningitis		13		2.0
Trauma		11		1.7
Others		25		3.8
Undetermined	367		56.5
Cataract		54		8.3
Glaucoma		32		4.9
Abnormality since birth		275		42.3
Others		6		0.9
Total	650	650	100	100