Cataract Treatment — How It Works, Benefits & Recovery — Procedure Guide, Recovery & Risks | MyMedicPlus

A cataract is clouding of the natural crystalline lens of the eye, causing progressive blurring of vision, glare, and colour desaturation. Cataract surgery is the only effective treatment — eyedrops, diet, or glasses cannot reverse lens clouding. The standard procedure is phacoemulsification: ultrasonic energy delivered through a 2–3 mm corneal incision liquefies the hardened lens nucleus, which is aspirated from the eye. A foldable intraocular lens (IOL) is then inserted through the same small incision and unfolds within the capsular bag, restoring a clear optical surface. Cataract surgery is the most frequently performed surgical procedure worldwide — approximately 20 million operations annually — with consistently excellent outcomes. A cataract is an opacity of the natural crystalline lens of the eye, causing progressive, painless blurring of vision, increased glare, reduced contrast sensitivity, and colour desaturation. Cataracts are the leading cause of reversible blindness worldwide — the WHO estimates 94 million people are visually impaired from cataracts. Ageing is the most common cause (nuclear or cortical senile cataract); other causes include diabetes, steroid use, trauma, uveitis, and congenital rubella. Cataract surgery is the only effective treatment — no pharmacological intervention reverses lens opacity. It is the most commonly performed surgical procedure in the world, with over 28 million cataract surgeries performed annually. The modern standard technique is phacoemulsification (phaco): ultrasound energy is used to emulsify the opaque lens, which is aspirated, and a clear artificial intraocular lens (IOL) inserted into the remaining capsular bag. The procedure is performed by ophthalmologists under topical anaesthesia as a day-case procedure.

Surgery is indicated when cataract-related visual impairment significantly affects the patient's daily activities, including driving, reading, work, and independent living. Specific visual triggers include best-corrected visual acuity worse than 6/12–6/18, disabling glare, difficulty with contrast in low light, and monocular diplopia. NICE guidance (UK) recommends prompt surgery without arbitrary wait-for-maturity policies. Hyper-mature cataracts causing raised intraocular pressure (phacolytic or phacomorphic glaucoma) require urgent surgery. Pre-operative ocular assessment includes biometry (IOLMaster or Lenstar) for IOL power calculation, slit-lamp examination, and fundus assessment to exclude co-existing retinal disease that would limit post-operative visual gain. Cataract surgery is indicated when cataract-related visual impairment significantly affects a patient's daily activities including driving, reading, and independent living. Specific indicators include best-corrected visual acuity worse than 6/12–6/18 in the better eye, disabling glare (particularly affecting night driving), difficulty with contrast sensitivity tasks, rapid refractive shift causing frequent spectacle prescription changes, or patient distress about visual quality. The UK Royal College of Ophthalmologists does not set a fixed visual acuity threshold — patient-reported functional disability is the primary criterion. Surgery is also indicated for cataract-induced secondary glaucoma (phacolytic or phacomorphic) and when a dense cataract prevents adequate retinal assessment or laser treatment for diabetic retinopathy or macular degeneration. Surgery is bilateral but staged, with the second eye operated 2–4 weeks after the first. Contraindications include active ocular infection, uncontrolled glaucoma, and corneal disease that would prevent adequate wound healing.

Anaesthetic eye drops (oxybuprocaine or proxymetacaine) numb the eye surface. The patient is awake throughout and sees only light and movement during the procedure. A 2–3 mm clear corneal incision is made. Continuous curvilinear capsulorhexis (CCC) — a circular tear in the anterior lens capsule — provides controlled access to the lens. Phacoemulsification handpiece breaks up the nucleus using 40,000 Hz ultrasonic vibration; the emulsified material is aspirated. Residual cortex is removed with an irrigation/aspiration probe. A foldable acrylic or silicone IOL (monofocal, multifocal, extended depth-of-focus, or toric) is injected through the incision and unfolds in the capsular bag. The corneal wound is self-sealing. Total operating time is 15–30 minutes; the patient returns home within 1–2 hours. Anaesthetic eye drops numb the eye surface. The patient is awake, seeing only light and movement during the procedure. A 2–3 mm clear corneal incision is made at the limbus. Continuous curvilinear capsulorhexis (CCC) — a circular tear in the anterior lens capsule — creates a window into the lens nucleus. Hydrodissection separates the nucleus from the capsule, allowing the phacoemulsification probe (ultrasound tip within a sleeve) to be inserted. Ultrasound energy emulsifies the nucleus using a divide-and-conquer or phaco-chop technique, and the emulsified material is aspirated simultaneously through a coaxial irrigation-aspiration system. Cortical material is then removed with a coaxial irrigation-aspiration handpiece. The capsular bag is injected with ophthalmic viscosurgical device (OVD) to maintain shape, and the IOL — folded in its inserter cartridge — is injected through the same 2–3 mm incision and unfolds within the bag. The OVD is removed, the incision is hydrated to achieve watertight self-sealing closure, and antibiotic drops instilled. Total procedure time is 15–25 minutes.

Cataract surgery achieves 6/12 or better unaided or corrected visual acuity in over 95% of eyes without co-existing ocular pathology. Visual improvement is typically noticeable within 24–48 hours and stabilises over 4–6 weeks. Patient satisfaction exceeds 95% in most series. Premium IOL options include: toric IOLs (correct pre-existing astigmatism), multifocal IOLs (reduce spectacle dependence for both distance and near), and extended depth-of-focus (EDOF) IOLs (continuous range of vision with fewer halos than multifocal). Recent evidence also shows cataract surgery reduces dementia risk and fall rates in older patients, attributable to improved vision and social engagement. The risk of serious vision-threatening complications is below 0.5% at high-volume centres. Cataract surgery achieves 6/12 or better unaided or corrected visual acuity in over 95% of eyes without co-existing ocular pathology. Visual improvement is typically noticeable within 24–48 hours and fully stabilises over 4–6 weeks. Patient satisfaction consistently exceeds 95% in NHS audit data. Premium IOL options include monofocal, extended-depth-of-focus (EDOF), and multifocal IOLs that reduce spectacle dependence for distance, intermediate, and reading vision. Toric IOLs correct pre-existing corneal astigmatism, improving unaided vision further. Restoration of functional vision has documented secondary benefits including reduced falls and hip fracture risk, improved cognitive function, and increased quality-adjusted life years (QALYs). The cost-effectiveness of cataract surgery is among the highest of any healthcare intervention — WHO estimates a DALY (disability-adjusted life year) averted at under USD 20 in high-volume settings.

Serious complications are uncommon but include posterior capsule rupture with vitreous loss (1–2%), which may require vitrectomy and affects final visual acuity. Endophthalmitis (bacterial infection inside the eye) occurs in 0.03–0.05% and is a surgical emergency requiring urgent intravitreal antibiotic injection; cefuroxime intracameral injection at the end of surgery reduces this risk by 75%. Posterior capsule opacification (PCO or 'secondary cataract') affects 10–20% of patients within 1–5 years and is treated with a painless 5-minute Nd:YAG laser capsulotomy in clinic. Elevated intraocular pressure, corneal oedema, and macular oedema (Irvine-Gass syndrome) are usually self-limiting with appropriate post-operative medication. Serious complications are uncommon. Posterior capsule rupture with vitreous loss occurs in 1–2% of procedures and may require a vitrectomy, with some risk to final visual acuity. Endophthalmitis (bacterial infection inside the eye) occurs in 0.03–0.05% and is a surgical emergency requiring urgent intravitreal antibiotic injection. Cystoid macular oedema (swelling of the central retina) occurs in 1–2% and usually resolves with topical NSAID treatment. Posterior capsule opacification (secondary cataract) — clouding of the retained posterior capsule — develops in 20–50% of patients over 2–5 years and is treated definitively with YAG laser capsulotomy as a 5-minute outpatient procedure. Corneal oedema is usually transient but can be persistent in patients with pre-existing Fuchs' endothelial dystrophy. Retinal detachment risk is modestly elevated (0.5–1.5%) in highly myopic eyes for several years after surgery.

An eye shield is worn overnight after surgery to prevent accidental rubbing. Antibiotic eye drops (chloramphenicol or ofloxacin) and anti-inflammatory drops (prednisolone acetate or ketorolac) are instilled 4 times daily for 4–6 weeks to prevent infection and inflammation. Vision typically improves within 24–48 hours though fluctuation is normal for 1–4 weeks. Swimming and eye make-up are avoided for 2 weeks. Driving is permitted when vision in both eyes meets the legal minimum standard (6/12 Snellen or better). Glasses are prescribed 4–6 weeks post-operatively once refraction has stabilised. Second-eye surgery is typically performed 1–4 weeks after the first, once the first eye has recovered. An eye shield is worn overnight to prevent accidental rubbing. Antibiotic eye drops (chloramphenicol or ofloxacin) and steroid anti-inflammatory drops (prednisolone acetate) are instilled 4 times daily for 4–6 weeks to prevent infection and inflammation. Vision typically improves noticeably within 24 hours, reaching near-final quality at 4–6 weeks when spectacle prescription can be finalised. Patients should avoid water getting directly into the operated eye for 2 weeks — showering with the eye closed and avoiding swimming for 4 weeks. Driving may resume once vision meets the required standard in both eyes (6/12 or better). Heavy lifting and strenuous exercise are restricted for 1–2 weeks. Patients are reviewed at 24–48 hours post-operatively for pressure check and wound inspection, and at 4–6 weeks for final assessment and spectacle prescription if needed.