Purpose: To determine the causes of severe visual impairment and blindness in children in schools for the blind in southern Karnataka state of India. Method: Children aged less than 16 years with a visual acuity of < 6/60 in the better eye, attending the residential schools for the blind were examined in 2005–2006, in the Karnataka state in the south of India. History taking, visual acuity estimation, external ocular examination, retinoscopy, and fundoscopy were done on all students. Refraction and low vision work-up done where indicated. The anatomical and etiological causes of severe visual impairment (< 6/60–3/60) and blindness (< 3/60 in the better eye) were classified using the World Health Organization's prevention of blindness programs' record system. Results: A total of 1,179 students were examined, 891 of whom fulfilled the eligibility criteria. The major anatomical sites of visual loss were congenital anomalies (microphthalmos, anophthalmos) (321, 35.7%), corneal conditions (mainly scarring due to vitamin A deficiency, measles, trauma) (133, 14.9%), cataract or aphakia in 102 (11.4%), and retinal disorders (mainly dystrophies) in 177 children (19.9%). Nearly one-fourth of children were blind from conditions which could have been prevented or treated (27.8%), 87 of whom were referred for surgery. Low vision devices improved near acuity in 27 children (3%), and 43 (4.8%) benefited from refraction. Conclusions: Congenital anomalies, cataract, and retinal conditions account for most of the blindness in children.