A cataract is a cloudy area in the lens of the eye that impairs vision. Cataracts are most commonly due to aging but may also be caused by trauma to the eye, radiation exposure, conditions present from birth or complications from other conditions; risk factors include diabetes, longstanding corticosteroid use, obesity, other eye conditions, dietary deficiencies, smoking tobacco, prolonged sunlight exposure and alcohol use. Three main types are recognized by where the clouding occurs in the lens: nuclear cataracts at the center, cortical cataracts in the outer part, and posterior subcapsular cataracts at the back.
Facts
Condition Classchronic, degenerative, ocular 1 Causative AgentMost commonly age-related lens clouding; also caused by trauma to the eye, radiation exposure, conditions present from birth or complications from other conditions such as diabetes; no single causative agent. 1 PrevalenceThe World Health Organization lists cataracts, alongside refractive errors, among the leading causes of vision impairment and blindness worldwide; cataracts account for an estimated 94 million of the roughly 1 billion people globally living with preventable or unaddressed vision impairment or blindness, and about one in two people worldwide who need cataract surgery lack access to it. 2 Disputed
First Described (Era)Scholars dispute which culture first described or performed cataract surgery. A Sanskrit account attributed to the physician Sushruta describes the couching technique, but neither the authorship nor the exact date of the underlying Sushruta Samhita can be established with certainty. The Greek philosopher Chrysippus of Soli (circa 279 to 206 BCE) left an early explicit written account of couching in Greek sources. A modern historical review concludes it is impossible to say which nation, or which individual, first performed a cataract operation. 3 Genuinely disputed which culture first described or performed cataract surgery; see the linked open question. Cross-Tradition Connections
Sources
Open Questions (1 open question)
Which culture first described or performed cataract surgery?
Indian tradition credits the physician Sushruta with the earliest description of couching, but neither the authorship nor the exact date of the underlying Sushruta Samhita can be established with certainty; the earliest surviving explicit Greek written account is attributed to the philosopher Chrysippus of Soli (circa 279 to 206 BCE). A modern historical review concludes it is impossible to say which nation, or which individual, first performed a cataract operation.
What would resolve this A securely dated manuscript or archaeological find fixing the Sushruta Samhita composition to a specific era relative to Chrysippus, or a specialist historiographical consensus resolving the priority question.
Medical HistoryAnnals of Translational Medicine: The History of Cataract Surgery
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