Cataract surgery (phaco and IOL): an OR 101 guide
Reviewed by Rodnie Oro, cath lab charge nurse · Last reviewed: October 2026 · Education only, not medical advice
Cataract surgery in one minute
What it is: surgery to remove a cloudy lens (cataract) through a tiny cut and replace it with a clear artificial lens (IOL).
Who it is for: people whose cataract affects their sight and daily life.
Main risks: infection inside the eye (rare), swelling, raised pressure, lens capsule tear, retinal detachment (rare), clouding later.
Usually: under local anaesthetic, 15–30 minutes, home the same day.
On this page: What is cataract surgery? · Who is it for? · When is it done? · Step by step · Recovery · Risks · Kit list · First time in theatre? · FAQ
What is cataract surgery?
The lens inside the eye focuses light. A cataract is clouding of the lens that blurs vision.
In cataract surgery (phacoemulsification) the surgeon:
- makes tiny cuts at the edge of the clear front of the eye
- opens the front of the lens capsule
- breaks up the cloudy lens with ultrasound and removes it
- places a folded intraocular lens (IOL) in the capsule, where it unfolds
The lens power is chosen from measurements before surgery, per device and operator.
New to the acronyms? See the Cath Lab Abbreviations A–Z.
Who is it for?
It may be considered for people with:
- cataract affecting vision and daily activities
The decision is made by your eye team with you, talking through the reasons, the expected result, the alternatives and the risks.
When is it done?
Most operations are planned; some are urgent. Before it, you usually have:
- eye measurements (biometry) to choose the lens power
- an eye examination
- a review of medicines, as per centre protocol
- a chance to ask questions and give consent
Step by step
1. Getting ready
Team brief and WHO checklist first, including the correct eye marked. The anaesthetic team and ODP give the anaesthetic (usually local: drops or an injection around the eye, sometimes with sedation, as per centre protocol); eye drops and antibiotics are given as per centre protocol. The circulating practitioner checks positioning, pressure areas, the diathermy plate and warming. The scrub practitioner sets up the instrument trolley and does the first count. The lens check (type, power, eye) is done against the biometry, and the microscope and phaco machine are checked.
2. Access
Tiny cuts at the edge of the cornea; no stitches are usually needed.
3. Replacing the lens
- A. Cloudy lens. The cloudy lens is seen under the microscope.
- B. Phaco. The lens is broken up with ultrasound and removed.
- C. Lens removed. The empty capsule is cleaned.
- D. IOL placed. The folded lens is placed and unfolds in the capsule.
The patient is usually awake; the team talks to them calmly and asks them to keep still.
4. Finishing
The cuts are checked for leaks and antibiotics given as per centre protocol. A shield may be placed. The lens details are logged and the patient goes home with drops and instructions.
Recovery and aftercare
- Same day: home the same day with a shield or drops.
- Drops: as prescribed for some weeks.
- Vision: often better within days.
- Avoid: rubbing the eye and swimming for a short time.
- Glasses: a new prescription after a few weeks.
- Urgent help: for increasing pain, redness or worse vision.
Contact the eye unit urgently if you have increasing pain, worsening vision, a red eye, flashing lights or a shadow in your vision.
Risks and complications
Your team will explain the risks that apply to you. Possible problems include:
- infection inside the eye (rare but serious)
- swelling of the cornea
- raised eye pressure
- tear in the lens capsule, sometimes needing more surgery
- retinal detachment (rare)
- clouding behind the lens later, treated with laser
Theatre kit list (printable)
Example kit list
Every theatre has its own protocol, and sizes and doses vary.
- operating microscope
- phaco machine and handpieces, settings per device and operator
- intraocular lens, type and power per biometry, per device and operator
- lens injector
- viscoelastic, per surgeon
- fine eye instruments and speculum
- antibiotics, as per centre protocol
Procedural steps
- Team brief, WHO sign in; eye marked; lens check; anaesthetic
- Positioning; drape; speculum; count
- Tiny cuts; capsule opened
- Phaco: lens removed; capsule cleaned
- IOL injected; position checked
- Cuts checked; antibiotics; lens logged; sign out and discharge advice
First time in theatre?
đź’ˇ First-time tip
- Know your role. Scrub, circulating, anaesthetic and ODP each have their own checks; ask at the team brief.
- Counts matter. Swabs, needles and instruments are counted before, during and at closure; speak up if one is missing.
- Microscope. Drape the operating microscope sterile and balance it before the case.
- Lens check. Read back the lens type, power and side against the plan before opening, and log it.
- Stillness. Patients are often awake; keep theatre calm and quiet.
FAQ
Will I be awake?
Usually; the eye is numbed and you will not see the details.
Does it hurt?
Most people feel pressure, not pain.
Will I need glasses?
Often for reading or some distances.
Related guides
Sources
All checked on 14 October 2026. Each page's own date is shown where it gives one.
- NICE. Cataracts in adults: management (NG77). nice.org.uk/guidance/ng77
- NHS. Cataract surgery. nhs.uk/conditions/cataract-surgery
- StatPearls (NCBI Bookshelf), search: cataract surgery. ncbi.nlm.nih.gov/books
- The Royal College of Ophthalmologists. www.rcophth.ac.uk
- World Health Organization. Surgical Safety Checklist. who.int
Disclaimer
Education only. This page is for general education for healthcare students, theatre staff and curious readers. It isn't medical advice and doesn't replace advice from your own doctor, surgical team or local unit protocols. Equipment and medicines are described generically. No product or manufacturer is recommended. If you think someone is having a medical emergency, call 999.
Disclosure: I work in the medical device industry. This page is independent education and isn't sponsored or reviewed by any company.
All diagrams on this page are original illustrations created for rodnieoro.com.
