A population-based aetiological study was carried out on 6 to 14 years-old severely visually handicapped children in Hungary. Of the 547 recorded cases 491 (90%) were included in the analysis. Eleven aetiological groups were separated: isolated cataracts (16.7%), congenital abnormalities of the eye (15.1%), high myopia +/- retinal detachment and other cases (13.4%), retinopathy of premature (11.0%), choroidoretinal degenerations (10.0%), syndromes (9.6%), nystagmus and/or hypermetropia (9.0%), isolated and complicated optic atrophy (6.7%), postnatal causes (4.9%), retinoblastoma (1.8%), prenatal causes (1.8%). A significantly higher rate of previous induced abortions was found in the group of retinopathy of premature. Perinatal damage syndrome and Mendelian monogenic defects are the two most common aetiological categories in the origin of severe visual handicaps in Hungary.