Cataracts: History and Discovery
A cataract is a clouding of the eye's natural lens that scatters and blocks incoming light, and its treatment is one of the oldest surgical procedures known to medicine. For more than two thousand years the only remedy was couching — using a needle to push the clouded lens down and out of the line of sight rather than removing it — a technique described in the ancient Indian Sushruta Samhita and practiced across Babylon, Egypt, Greece, and Rome. The modern era began when the French surgeon Jacques Daviel performed the first deliberate extraction of a cataract in 1747, and it was transformed again when Sir Harold Ridley implanted the first artificial intraocular lens in 1949 and Charles Kelman introduced phacoemulsification in 1967. This page traces that arc from a curved bronze needle to one of the most common and successful operations performed today.
Table of Contents
- What a Cataract Is and the Word's Origin
- Couching: The Oldest Surgery
- Suśruta and the Sushruta Samhita
- Babylon, Egypt, Greece, and Rome
- Jacques Daviel and the First Extraction (1747)
- Harold Ridley and the Intraocular Lens (1949)
- Charles Kelman and Phacoemulsification (1967)
- From Landmark to Routine: Cataract Surgery Today
- Research Papers and References
- Connections
What a Cataract Is and the Word's Origin
The lens of the eye sits just behind the iris and is normally clear, focusing light onto the retina much as a camera lens focuses an image onto film. A cataract is the progressive clouding of that lens. As the orderly proteins that keep the lens transparent clump and discolour with age — or, less commonly, after injury, certain medications, or as a complication of conditions such as diabetes — the lens grows hazy and yellow-brown, scattering light and dulling and blurring vision. Most cataracts develop slowly over years; left untreated they are a leading cause of blindness worldwide, yet they are almost entirely reversible with surgery.
The name itself records how the disease once looked to those who described it. The English word cataract comes through the Latin cataracta, meaning "waterfall" or "floodgate," from the Greek katarrhaktes — an adjective meaning "down-rushing" that named both a waterfall and a portcullis (the heavy grated gate dropped to bar a castle entrance). Both senses survive in the medical term. Lexicographers and historians of ophthalmology note that the "waterfall" image may evoke the white, churning appearance of an advanced (mature) cataract, or the sensation of looking out through rushing water, while the "portcullis" sense captures the older idea of an obstruction lowered in front of the sight. Scholars are honest that no single explanation is certain; the etymology is well attested even where the original metaphor is not.
That uncertainty is itself instructive. For most of history, physicians could see only the outward whitening and reasoned that some opaque matter had descended in front of the lens; the truth — that the lens itself becomes cloudy — was not firmly established until the seventeenth and eighteenth centuries, and it is precisely this corrected understanding that made modern extraction surgery possible.
Couching: The Oldest Surgery
The earliest treatment for cataract was not removal but displacement, a procedure called couching (from the French coucher, "to lay down"). The surgeon, working without anaesthesia, passed a sharp needle or lancet through the white of the eye near the edge of the cornea and used it to push the clouded lens downward and backward, dislodging it from the pupil and letting it sink into the vitreous cavity at the bottom of the eye. The lens was never taken out; it was simply moved out of the line of sight so that light could once again reach the retina.
Couching could restore a crude, unfocused form of vision: with the lens displaced, the patient was left severely far-sighted and could perceive light, shapes, and movement, though sharp focus was impossible without the thick spectacles that later centuries would supply. The risks were severe and frequent — bleeding, infection, glaucoma, and detachment of the displaced lens often led to inflammation and permanent blindness — yet for a person who was already blind from a mature cataract, even partial sight was a profound gain, and the operation was performed for millennia across a vast geographic range.
Because it required only a steady hand and a single fine instrument, couching spread along trade and pilgrimage routes and persisted in some regions into the twentieth century, long after superior techniques existed. Its extraordinary longevity — arguably the longest continuously practiced surgical operation in human history — is what gives cataract surgery its claim to be among the oldest surgeries known.
Suśruta and the Sushruta Samhita
The most detailed early account of couching appears in the Sushruta Samhita ("Compendium of Suśruta"), a foundational Sanskrit treatise of Indian surgery attributed to the surgeon Suśruta. Suśruta is traditionally dated to around the sixth century BCE, though scholars caution that the surviving text was compiled and revised over a long period and that the historical figure's exact dates are uncertain; the attribution and the early date should be read as the traditional account rather than a firmly fixed one. The work's later section, the Uttaratantra, contains the cataract description.
In that account the surgeon seats the patient, warms the eye, and introduces a curved needle to push the opaque "phlegmatic" matter (the clouded lens) away from the pupil, displacing it until the patient can again see surrounding objects. The text describes after-care in vivid practical detail — the eye is soaked with warm clarified butter (ghee) and bandaged, and the patient is told to rest and avoid coughing, sneezing, and exertion that might let the lens spring back. Modern historians of ophthalmology, including Grzybowski and Ascaso in Acta Ophthalmologica, treat this as one of the earliest systematic descriptions of intraocular surgery on record.
Suśruta is honoured in the history of medicine as a pioneer of surgery more broadly — the same compendium describes reconstructive procedures and a large catalogue of instruments — and the cataract operation is among its most celebrated chapters. From the Indian subcontinent the technique is documented spreading eastward; historical accounts record couching being carried into China, where it flourished under the Sui and Tang dynasties.
Babylon, Egypt, Greece, and Rome
Cataract and its treatment appear across the ancient Near East and Mediterranean world. The Code of Hammurabi from ancient Babylon (c. 18th century BCE) famously sets fees and penalties for a surgeon who "opens an abscess of the eye" or operates on the eye with a bronze lancet — a passage often cited as evidence that some form of eye surgery was practiced and regulated, though scholars debate whether the specific operation described is cataract couching. In ancient Egypt, eye disease was widespread and medical papyri record numerous ophthalmic remedies; whether the Egyptians performed couching itself is less certain, but their broad concern with diseases of the eye is well documented.
In the classical world the evidence is firmer. The Greco-Roman medical encyclopaedist Aulus Cornelius Celsus, writing De Medicina in the first century CE, left a clear and oft-quoted description of the couching operation — the needle introduced through the eye, the clouded lens pressed downward and held until it stayed put — that closely parallels the Indian account and shows the procedure was understood and practiced in Rome. The work of later Greek physicians such as Galen continued to shape how cataract (conceived as a humour descending in front of the lens) was explained for more than a thousand years.
What is striking is the independence and convergence of these traditions: surgeons separated by thousands of miles and centuries arrived at the same essential maneuver — displace, do not remove — because it was the only intervention possible with the instruments and anatomical understanding of the age. Couching remained the standard of care, essentially unchallenged, until the middle of the eighteenth century.
Jacques Daviel and the First Extraction (1747)
The decisive break with two millennia of couching came from the French surgeon Jacques Daviel (1696–1762). Daviel had himself been a practitioner of couching and grew dismayed by its frequent failures — displaced lenses that floated back, eyes lost to inflammation. Reasoning that the clouded lens should be removed rather than merely pushed aside, he experimented on cadaver eyes and developed a method to open the cornea and extract the lens material directly.
On 8 April 1747, attending a patient (a wigmaker named Garion) in whom couching had failed during the operation, Daviel committed to extraction instead: he opened the lower cornea widely, entered the anterior chamber, and removed the opaque lens through the incision. This is recognized as the first deliberate extracapsular cataract extraction — removing the cloudy lens while leaving the thin posterior capsule that surrounds it in place. Daviel refined the technique on many further patients and presented his results to the medical community in 1752, by which time he was performing it routinely with results that, for the era, were remarkable.
Daviel's innovation founded modern cataract surgery: for the first time the offending lens was taken out of the eye rather than relocated within it. Historians such as Obuchowska and Mariak credit him as the inventor of extracapsular extraction, and his approach — extract the lens, leave the capsule — remains the conceptual ancestor of the operation performed today. It is worth noting that some surgeons in Europe had attempted lens removal before 1747; Daviel's distinction lies in developing extraction into a deliberate, repeatable, and taught procedure that displaced couching as the operation of choice.
Harold Ridley and the Intraocular Lens (1949)
Removing the cataractous lens solved the problem of the opacity but created a new one: an eye without its lens (an aphakic eye) cannot focus, leaving the patient dependent on extraordinarily thick, distorting "cataract glasses" or, later, contact lenses. The landmark that solved this problem was the invention of the artificial intraocular lens (IOL) — an implant placed inside the eye to take over the focusing job of the natural lens — by the British ophthalmologist Sir Harold Ridley (1906–2001).
Ridley's insight famously grew out of the Second World War. Treating Royal Air Force pilots whose cockpit canopies, made of the plastic polymethyl methacrylate (PMMA, sold as Perspex), had shattered in combat, he observed that splinters of the material lodged in their eyes were tolerated for years without provoking the chronic inflammation that glass or metal would cause. Ridley concluded that PMMA was inert enough to remain permanently inside the eye, and that a lens fashioned from it could replace the one removed in cataract surgery. He implanted the first intraocular lens at St Thomas' Hospital in London; the operation is dated to 29 November 1949 (with the permanent lens completed in a follow-up procedure in 1950).
Ridley's idea was met with years of skepticism and outright hostility from much of the profession, and early complications — arising from lens design and surgical technique, not from the PMMA itself — slowed acceptance through the 1950s and 1960s. Vindication came gradually, and by the 1970s and 1980s the intraocular lens had become standard. Accounts such as Lim and Mishra's in Cureus recount how a wartime observation of inert canopy plastic became one of the most consequential ideas in the history of surgery; Ridley is now widely called the father of the intraocular lens and was knighted late in his life for the achievement.
Charles Kelman and Phacoemulsification (1967)
Through the mid-twentieth century, even successful cataract extraction required a large incision — often nearly half the circumference of the cornea — followed by stitches and a long, restricted recovery. The breakthrough that shrank the operation to a tiny opening was phacoemulsification ("phaco"), developed by the American ophthalmologist Charles Kelman (1930–2004).
Kelman's idea, which he later said was inspired by the ultrasonic probe his dentist used to clean his teeth, was to break up the hard cataract inside the eye using high-frequency ultrasonic vibration and simultaneously aspirate the emulsified fragments through a slender hollow needle. Because the lens is liquefied and suctioned out piecemeal, the surgeon needs only a very small incision rather than a large one. After laboratory development — an early success removing a cataract from a cat's eye in 1966 — Kelman performed the first phacoemulsification procedures in human patients in 1967; he and his collaborator filed the foundational patent that same year.
Like Ridley's implant, phaco was at first controversial and technically demanding, and it took roughly a decade to gain wide adoption, becoming the dominant technique through the late 1970s and 1980s. Its impact was transformative: the small, often self-sealing incision meant fewer stitches, less astigmatism, faster healing, and the practical possibility of same-day outpatient surgery. Combined with Ridley's intraocular lens — modern foldable IOLs can be inserted through the same tiny phaco incision — Kelman's method, profiled in modern histories such as Awad and colleagues' account in Cureus, is the direct basis of the cataract operation experienced by most patients today.
From Landmark to Routine: Cataract Surgery Today
The cumulative result of these advances is that cataract surgery has become one of the most common, safest, and most successful operations in all of medicine. A typical modern procedure takes well under an hour, is performed under local or even topical (eye-drop) anaesthesia with the patient awake, and unfolds in a sequence whose logic descends directly from the history above: the surgeon makes a tiny incision, uses phacoemulsification to break up and remove the clouded lens (Kelman, 1967) while preserving the surrounding capsule (the extracapsular principle of Daviel, 1747), and slips a folded intraocular lens into that capsule (Ridley, 1949), where it unfolds to restore focus.
The improvement over couching is total. Where the ancient operation left a patient blurred, far-sighted, and at high risk of losing the eye, contemporary surgery routinely restores sharp vision — and modern lens choices can correct pre-existing near-sightedness, far-sightedness, and astigmatism at the same time, so that many patients see better afterward than they had in decades. Tens of millions of these operations are performed worldwide each year, and they are a mainstay of global efforts to reverse avoidable blindness.
It is a rare and satisfying story in the history of medicine: a single disease, treated for more than two thousand years by displacing the lens with a needle, transformed within two centuries into a quick, precise, sight-restoring procedure. The thread running from Suśruta's curved needle, through Daviel's incision, Ridley's canopy plastic, and Kelman's ultrasonic probe, to the operating rooms of today is one of the clearest demonstrations of how patient observation and bold innovation compound across generations.
Research Papers and References
The references below combine peer-reviewed historical reviews (with real DOIs and PMIDs where available) with curated PubMed topic-search links into the history-of-ophthalmology literature. Ancient primary texts — the Sushruta Samhita, the Code of Hammurabi, and Celsus' De Medicina — are named in the article as historical sources rather than as modern citations. Each external link opens in a new tab.
- Grzybowski A, Ascaso FJ. Sushruta in 600 B.C. introduced extraocular expulsion of lens material. Acta Ophthalmologica. 2014;92(2):194-197. — doi:10.1111/aos.12037 (PMID 23464869)
- Obuchowska I, Mariak Z. Jacques Daviel — the inventor of the extracapsular cataract extraction surgery. Klinika Oczna. 2005;107(7-9):567-571. — PMID 16417025
- Grzybowski A, Ascaso FJ, et al. Extracapsular cataract extraction in Europe prior to Jacques Daviel. Acta Ophthalmologica. 2023. — doi:10.1111/aos.15282
- Lim KS, Mishra A. Sir Harold Ridley as the Pioneer of Intraocular Lenses: His Inspiration Drawn From World War II Pilots. Cureus. 2024;16(9):e68722. — doi:10.7759/cureus.68722 (PMID 39371888)
- Awad AA, Alkorbi HA, Abu Serhan H. Charles Kelman: The Father of Phacoemulsification. Cureus. 2024;16(6):e61727. — doi:10.7759/cureus.61727 (PMID 38975537)
- Couching for cataract — history and practice of the ancient technique — PubMed: couching cataract history
- Suśruta and the history of ophthalmology in ancient India — PubMed: Suśruta ophthalmology ancient India
- History of cataract surgery — from couching to extraction — PubMed: history of cataract surgery
- Harold Ridley and the invention of the intraocular lens — PubMed: Harold Ridley intraocular lens history
- Charles Kelman and the development of phacoemulsification — PubMed: Kelman phacoemulsification history
- Etymology and historical descriptions of cataract — PubMed: cataract etymology and history
- Cataract in the ancient world — Celsus, Greece, and Rome — PubMed: cataract in the ancient world
- Intraocular lens development and modern cataract surgery outcomes — PubMed: intraocular lens and modern cataract surgery
- Evolution of phacoemulsification and small-incision cataract surgery — PubMed: phacoemulsification and small-incision surgery
External Authoritative Resources
- American Academy of Ophthalmology Museum — Cataract Surgery: Couching to Phaco
- National Eye Institute (NIH) — Cataracts
- EyeWiki (American Academy of Ophthalmology) — History of Cataract Surgery