Blindness and visual impairment
ContextWorldwide, about 217 million people have low vision, and about 36 million are blind:
Age-Related Macular Degeneration (ARMD)Unoperated cataract remains the leading cause of blindness in low- and middle-income countries. (WHO, 2017)
CataractUnoperated cataract remains the leading cause of blindness in low- and middle-income countries. (WHO, 2017)
Risk factors include:
Corneal blindnessIncludes Xerophthalmia (nutritional blindness), Trachoma, corneal ulcer, and injuries (accidental, iatrogenic). (Dahal, 2018)
Onchocerciasis (River blindness)Caused by a roundworm infection spread by black flies.
The Farmer and Fisherman Who Lost His Sight to River Blindness
TrachomaA chronic, contagious infection that eventually causes blindness; manifests gradually. Tends to occur in clusters, infecting families or communities. WHO uses a SAFE (Surgery, Antibiotics, Face-washing, Environmental improvement) strategy against Trachoma. (Dahal, 2018)
Xerophthalmia/Vitamin A deficiency/Night BlindnessCaused by severe vitamin A deficiency, and described by pathologic dryness of the conjunctiva and cornea.
Deaf-Blind"Deaf-blindness refers to the combination of hearing and visual loss that severely impedes communication, education, employment, and independent living. While some deaf-blind individuals are totally deaf and blind, most deaf-blind people have different levels of vision and hearing loss." (NLS)
Play-by-play soccer for a deaf-blind person
Striped canes signify deaf-blindness
Library of Congress resources