Cataract Surgery (Phacoemulsification)

Cataract surgery (phacoemulsification) is an eye operation that removes a cloudy natural lens from inside the eye and replaces it with a clear artificial lens, restoring the ability to see sharply.

A cataract forms when the eye's natural lens — the transparent disc sitting just behind the pupil — gradually turns cloudy and yellow, blocking and scattering light before it can reach the retina (the light-sensing layer at the back of the eye). In phacoemulsification, the surgeon makes a tiny cut at the edge of the cornea (the clear front surface of the eye), then uses a very fine ultrasound probe to break the cloudy lens into small fragments and gently suction them out. An intraocular lens (IOL) — a small, permanent artificial lens — is then folded, inserted through the same small opening, and unfolded in place. No stitches are usually needed because the cut is self-sealing.

This surgery is performed when a cataract has grown cloudy enough to interfere meaningfully with daily life or when it causes other eye problems. The decision to operate is based on how much the cataract affects the patient's vision and quality of life, not on its appearance alone.

• Vision that has become blurry, hazy, or dim despite updated glasses.
• Glare and halos around lights, especially at night, making driving unsafe.
• Colors appearing faded or yellowed.
• Double vision in one eye caused by the cataract.
• Frequent changes in glasses or contact lens prescriptions due to the growing cataract.
• A dense cataract that prevents the doctor from examining or treating the retina properly.
• A cataract causing raised pressure inside the eye (glaucoma secondary to a swollen lens).

Phacoemulsification is not suitable for every patient or every type of cataract. Your eye doctor will decide after a thorough assessment.

• Very advanced ('hypermature') cataracts may require a different surgical technique rather than phacoemulsification.
• Certain corneal diseases may mean the eye cannot tolerate the ultrasound energy used in this procedure.
• Patients with very small pupils or other structural eye problems may need a modified approach.
• Active infection or severe uncontrolled inflammation inside the eye usually means surgery is postponed until the eye is stable.

Phacoemulsification is one of the most commonly performed eye surgeries and is generally considered safe, but like any surgical procedure it carries recognised risks.

• Posterior capsule opacification (PCO): the thin membrane behind the IOL gradually turns cloudy weeks to years later, causing blurred vision again — this is the most common long-term issue and is treated with a quick, painless laser procedure in the clinic.
• Inflammation (swelling) inside the eye in the days after surgery, usually managed with eye drops.
• Raised eye pressure shortly after surgery, usually temporary.
• Infection inside the eye (endophthalmitis) — rare but serious, requiring urgent treatment.
• Swelling of the central retina (cystoid macular oedema), which can temporarily blur central vision.
• Posterior capsule rupture during surgery, where the membrane holding the lens tears — this may change how the IOL is placed and may require additional steps.
• Dropped lens fragment falling to the back of the eye, needing a further operation.
• Corneal swelling (oedema), usually temporary.
• IOL moving out of position (dislocation) — uncommon but may need correction.
• Retinal detachment (the retina peeling away from the back of the eye) — rare but serious.
• Visual disturbances such as glare or halos from the IOL, especially at night.
• The need for glasses after surgery for near or distance vision, depending on the IOL chosen.

Preparing well for cataract surgery helps the procedure go smoothly and reduces the chance of complications. Your eye doctor and surgical team will give you personalised instructions, but the following covers what is typical in most hospitals.

Before the day of surgery, your doctor will usually ask you to stop wearing contact lenses for at least a week or two, because contact lenses can slightly alter the shape of the cornea and affect the measurements needed to choose the right IOL power. You will also be asked to avoid alcohol for at least a day or two before surgery. If you smoke, the team may advise stopping or reducing smoking ahead of surgery to support healing. Fasting is usually required — commonly nothing to eat or drink for several hours before the procedure — because a light sedative or injection near the eye may be used alongside local anaesthetic (numbing drops or an injection that blocks pain around the eye without making you fully unconscious). Your surgical team will tell you the exact fasting window.

If you take blood thinners, diabetes medication, or eye drops for glaucoma, your doctor will review these and advise which to continue and which to pause — never stop any medication on your own. Certain eye drops, usually containing antibiotics and anti-inflammatory medicines, are often started a few days before surgery to prepare the eye surface and reduce infection risk.

Pre-operative tests and measurements that are typically arranged include:

• Biometry (IOL power calculation): a painless scan, using light or ultrasound, that measures the length of the eye and the curvature of the cornea to calculate the exact power of the artificial lens needed.
• Slit-lamp examination: a detailed look at the front and back of the eye under a microscope to check the health of the cornea, iris, and retina.
• Eye pressure measurement (tonometry).
• Assessment of the pupil's ability to dilate (widen), since adequate dilation is needed during surgery.
• General health checks such as blood pressure and blood sugar measurement, and sometimes a basic blood test or ECG (electrocardiogram, a heart trace), depending on your age and health.

On the day of surgery, the steps typically proceed as follows:

• 1. You arrive at the eye centre and the team confirms your identity, which eye is being operated on, and reviews your consent.
• 2. Dilating eye drops are placed in the eye to widen the pupil — this usually takes around 20–30 minutes.
• 3. The area around your eye is cleaned and a sterile drape is placed over your face, leaving the eye exposed.
• 4. Local anaesthetic is applied — usually numbing drops, sometimes a small injection near the eye — so you feel no pain during surgery. You remain awake but relaxed; some hospitals offer a mild sedative through a drip.
• 5. The surgeon makes a very small, self-sealing incision at the edge of the cornea.
• 6. A circular opening is made in the front of the lens capsule (the thin bag that holds the lens).
• 7. The phacoemulsification probe is inserted; ultrasound energy breaks the cloudy lens into tiny pieces, which are gently suctioned out.
• 8. The empty lens capsule is cleaned and the folded IOL is inserted, then guided open inside the capsule.
• 9. The incision is checked — it usually seals without stitches. A protective shield is placed over the eye.
• 10. The entire procedure usually takes well under an hour for a straightforward case, though the time in the facility from arrival to discharge is longer.

Most patients go home on the same day as surgery. Vision is often blurry at first and improves over the following days to weeks as the eye heals and adjusts to the new lens. Your eye care team will schedule follow-up appointments — usually the next day, then at intervals over several weeks — to check that the eye is healing well and that the IOL is in position.

• A protective eye shield is worn immediately after surgery and typically kept on while sleeping for at least a week to prevent accidental rubbing.
• Antibiotic eye drops and anti-inflammatory eye drops are prescribed for several weeks to prevent infection and control swelling — it is important to follow the exact schedule given by your doctor.
• Avoid rubbing or pressing on the operated eye at all times in the early weeks.
• Keep water, soap, shampoo, and dust away from the eye, usually for at least one to two weeks — the team will advise when face washing and showering are safe.
• Strenuous activities, heavy lifting, and bending forward are usually restricted for a few weeks while the incision heals fully.
• Swimming and contact sports are typically avoided for several weeks; your surgeon will specify the timeline.
• Driving is not permitted until the doctor confirms your vision in the operated eye meets the required standard — this varies by person.
• If the eye becomes suddenly more painful, very red, or vision worsens after an initial improvement, contact the eye team immediately, as these can be signs of infection or other complications.
• A final glasses prescription, if needed, is usually given only after the eye has fully stabilised — this can take up to several weeks.
• If the second eye also has a cataract, the surgeon will usually wait until the first eye has recovered before scheduling the next operation.