Both genetic factors and diseases can cause blindness
Blindness among Infants: over 60% of cases are caused by inherited eye diseases, such as congenital cataracts, congenital glaucoma, retinal degeneration, optic atrophy and eye malformations.
Leading causes of blindness among Adults: glaucoma and age-related macular degeneration. A large portion of cases appear to be inherited. Researchers have mapped several genes for glaucoma and are starting to identify genes involved in macular degeneration.