Cataract surgery - How it is performed 

How it is performed 

Cataract surgery

Having a cataract removed is one of the most common operations in the UK. Consultant ophthalmologist Mark Wilkins explains what's involved.

Media last reviewed: 18/02/2012

Next review due: 18/02/2014

Meet the ophthalmic team

  • An optometrist examines eyes, tests sight and prescribes and dispenses spectacles and contact lenses. Optometrists are trained to recognise eye conditions and sight defects. 
  • An ophthalmic medical practitioner (OMP) is a medical doctor who specialises in eye care. They examine eyes, test sight, diagnose abnormalities and prescribe corrective lenses. 
  • An ophthalmologist is a medical doctor who specialises in eye conditions and their treatment. They mainly work in hospitals and hospital eye departments. 
  • A dispensing optician fits prescriptions for spectacles provided by optometrists, OMPs or ophthalmologists. They may also fit contact lenses. A dispensing optician does not carry out eye examinations. 
  • An orthoptist specialises in problems relating to eye movement and the eyes working together, including squintlazy eye and double vision
  • An ophthalmic nurse is a nurse who has developed skills in eye care. Ophthalmic nurses work in hospital eye departments.

Cataracts are removed using surgery. If you have cataracts in both eyes, you will have surgery on them on separate occasions. This gives the first eye time to heal and your vision time to return.

Most cataract operations are performed as day surgery under local anaesthetic, which means you can go home afterwards. Nearly all of your vision will return within two days of surgery but you will need someone to look after you for the first 24 hours after surgery. Read more about recovering from cataract surgery.

Pre-operative assessment

Before your operation, you will be referred to a specialist eye doctor (an ophthalmologist or ophthalmic surgeon). They will assess your eyes and general health.

During the assessment, your eyes are measured to prepare for the artificial lens that will replace your natural lens.


Cataract surgery is very common and can often be completed within 45 minutes.

Phacoemulsification is the most common cataract procedure and usually takes 15-30 minutes.

During phacoemulsification, your surgeon will put drops in your eye to dilate (widen) your pupil (the black circle at the centre of your eye). You will also be given a local anaesthetic (painkilling medication), which can be applied as eye drops or given as an injection into the tissue around the eye.

The surgeon makes a tiny incision (cut) in your cornea (the transparent outer layer on the front of your eye). A small probe that releases ultrasound waves (high-frequency sound waves) is inserted into your cornea to break the cataract up into tiny pieces. After the ultrasound probe has been removed, a new probe is inserted which sucks out the pieces of the cataract.

When the entire cataract has been removed, the surgeon inserts a small plastic lens through the incision in your cornea. The lens sits in the lens capsule, behind the pupil. The replacement lens is folded in half when it's inserted so it can fit through the incision in the cornea. When it is in place, it unfolds itself and adopts the natural position of the old lens.

Replacement lenses

When the cloudy lens is removed it is replaced with an artificial, clear plastic lens. This is called an intraocular implant, or intraocular lens (IOL).

Three types of IOL are available. Your ophthalmologist will help you to decide which type of lens will be best for you. The three types of lens are:

  • fixed strength lenses (monofocal), which are set for one level of vision, usually distance vision
  • multifocal lenses, which allow two or more different strengths, such as near and distance vision
  • accommodating lenses, which allow the eye to focus on both near and distant objects, in a similar way to the natural human lens

Multifocal and accommodating lenses are not usually available through the NHS. Glasses will always be required.

NHS funding for these types of lens will depend on your local primary care trust (PCT). Ask your GP or ophthalmologist about the type of lenses available in your area. If NHS funding is not available for these types of lenses, you may be able to pay to have them fitted privately.

Page last reviewed: 26/04/2012

Next review due: 26/04/2014


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The 3 comments posted are personal views. Any information they give has not been checked and may not be accurate.

Shirrmontana said on 21 July 2013

Having had cataracts for a few years, discussed the option of having them removed, I'm relatively young, so was told the op weould be straight forward and within a couple of days would have perfect distance vision.

It's now 2 weeks since the op and I still can't see properly/clearly out of the eye I had operated on. I went back to the Eye Hospital, they assured me everything was fine, am now on an intensive course of Steroids 1 week of every 2 hours day and night, next week 6 times daily, then another week 4 times days, another week of 3 times daily, then twice a day for a week, then once a day for a week, plus strong anti-biotic drops 4 times a day for 6 weeks. I have no infection, some inflammation at the back of the eye, but still can't see. it's like everything has a ghost, night time street light has flares coming out of them, definitely not what I expected. I can't see anything clearly either close up or distant and with the vision in my other eye poor because of cataracts I am now struggling to cope day to day. I'm praying this is only temporary, but please be aware, it's not the quick fix (if at all) it's made out to be.

Am now waiting to see if the operated eye clears, if not then I don't know what to do about the other, at this rate I'm going to be totally blind :(

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Uttambhai D Mistry said on 29 December 2012

I am in my mid-60s. I underwent cataract surgery in my left eye 10 days ago at the Royal Bolton Hospital. My post-operative follow-up was carried out yesterday by an ophthalmologist.

My right eye was eviscerated at young age following serious injury received from a car accident. I depended on my left eye which served me very well until a few months ago when I started to develop a cataract and my vision had become dim and cloudy.

Not having the security of any vision in my right eye, I was at first quite apprehensive when I had to decide whether to go ahead with a cataract surgery which had been offered to me. I need not have feared as the specialist surgeon who performed the operation was highly experienced. My pre-operative assessment was comprehensive. The operation took less than 30 minutes. At my follow-up appointment, the ophthalmologist told me encouragingly that the operation had gone very well indeed. He was able to put me at ease by answering all questions that had troubled me.

The staff at the Eye Unit were very helpful and caring at all stages. I would have no hesitation in recommending NHS cataract surgery.

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Mary Fisher said on 16 February 2012

I had cataract surgery this morning at St James', Leeds. My eye feels gritty and smarts a little and my vision isn't very good right now - I can't even wear my specs because of the eye 'patch'.
This video was very helpful in the weeks before the surgery and after watching it again I realise that my experience was exactly as shown in the film.
My expectation is that the results will be as good as expected and I look forward to having the second eye done.I can't praise the team -= from assessment to now - highly enough, they even coped with all my questions more than adequately. They are skilled at all levels of the profession.
Cataract surgery is recommended by this patient!

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