How is Cataract Surgery performed?

It’s the most common operation performed in the UK, with a high success rate in improving your eyesight.

Surgery is the only effective treatment for cataracts and for most individuals this is a straightforward operation, which lasts about 10 minutes, without the need for any needles/injections, as we numb the eye with drops.

What happens during surgery?

During the “keyhole” operation the surgeon makes a small cut in the eye and the cloudy lens is removed by an ultrasonic (phacoemulsification) probe which softens the lens with sound waves and removes the cataract.

The back layer of the lens is left behind. and replaced with a new lens implant (called an intraocular lens, or IOL for short). An artificial lens (implant) is then inserted to replace the cataract. Your new lens implant will be chosen specifically to match the prescription required for each eye and can help correct long or short sighted vision, if required. Sometimes a small stitch is put in the eye.

At the end of the operation, a pad or shield may be put over your eye to protect it. You can have monofocal lenses, which have a single point of focus. This means the lens will be fixed for either near or distance vision, but not both or you can have a multifocal or an accommodating lens, which allow the eye to focus on both near and distant objects. Please click here if you would like to learn more about the different lens options.

Following surgery most patients experience improved vision with no cloudiness, and colours you’re seeing should be back to normal but it can take 4 to 6 weeks to fully recover from cataract surgery.

We understand that every patient is unique and Ms Pearsall will recommend the treatment that is most suitable for the long term correction of your vision. She will ensure your surgical plan is the most optimal for you.

What is the likelihood of better vision?

After the operation you may read or watch TV almost straight away, but your vision may be blurred.

The healing eye needs time to adjust so that it can focus properly with the other eye, especially if the other eye has a cataract. The vast majority of patients have improved eyesight following cataract surgery.

Please note that if you have another condition such as diabetes, glaucoma or age-related macular degeneration your quality of vision may still be limited even after successful surgery.

Will my colour vision change?

Cataract in your eye scatters and absorbs blue light selectively. After surgery, your lens implant is very clear so a change in colour vision is common. This can be dramatic, especially in the early period after surgery, and can make colours look brighter or bluer than usual. You will adapt to your new vision in time.

Most lens implants have ultra violet (UV) blocking built in, but you can use sunglasses when outdoors in bright sunlight to block excess UV light reaching the retina. If you have an occupation where colour vision is critical, you should seek specific advice.

What complications can happen during surgery?

There are a very large number of possible complications after cataract surgery, but many are very rare and it is impossible to detail every single one. It is possible to require another operation or more surgery than planned during the operation. There is a very small risk of serious and permanent visual loss. There is a very tiny risk to the sight of the other eye.

  • Tearing of the thin lens membrane inside the eye (posterior capsular rupture) can allow the gel (vitreous) from the back chamber of the eye to come forward into the front chamber. This can result in reduced vision or other complications. Should this occur, additional surgery would be required (at the time of the cataract operation) to remove the vitreous gel from the front chamber of the eye. Also it might not be possible for the lens implant to be placed during the operation; if the implant cannot be inserted, it might be done as a later second operation but, in some cases, it might not be possible.
  • Loss of all or part of the cataract into the back of the eye requiring a further operation which may require a general anaesthetic.
  • Suprachoroidal haemorrhage or bleeding inside the eye which can be very serious and lead to total loss of the vision in the eye.
  • Damage to the other parts of the eye such as the iris or cornea.


What complications can happen after surgery?
  • Bruising of the eye or eyelids.
  • High pressure inside the eye.
  • Corneal decompensation – Damage or clouding in the cornea (the clear window on the front of the eye). This condition is usually treated with eye drops. I the worst case, a corneal transplant may be required if the clouding is permanent.
  • Incorrect strength or dislocation of the implant.
  • Swelling (waterlogging) or production of inflammatory fluid in the central part of the retina (cystoid macular oedema). This is usually mild and recovers within a few months even without treatment. We will watch it closely for any changes. More severe cases may require a long-term course of treatment and observation and in rare circumstances permanently damage your vision.
  • Detached retina – This when the back inside layer of the eye (the retina) peels off. This condition will require further surgery.
  • Endophthalmitis – this is a severe and usually painful infection inside the eye, which can lead to loss of sight or even loss of the eye. It would require a stay in hospital and treatment with eye drops.
  • Allergy to the medication used – this can cause itching and irritation, which goes once the eye drops have stopped or changed to an alternative.
  • Glaucoma – this is a rise in the eye pressure for the first day or so after surgery, which may require temporary treatment with extra eye drops.
  • Severe inflammation inside the eye (uveitis).
  • Serious infection inside the eye (endophthalmitis).
  • The lens implant can be dislocated into the wrong position or moves out of position. This would require further surgery.
  • The lens implant over many years can calcify or become cloudy or have deposits within it (very rare).
  • Refractive surprises – A patient may not get the expected post-operative vision and could be left long or short sighted, or have astigmatism requiring spectacles, contact lenses or, rarely, surgery or laser, to correct it.
  • Floaters are commonly seen after cataract surgery and, although annoying, are usually harmless.

However if you suddenly start to experience persistent flashing lights and/or increased/ new floaters, please attend A&E immediately since those can be symptoms of the beginnings of a retinal detachment. Timely retinal detachment surgery is usually successful in restoring vision.

  • The upper eyelid can become droopy.
  • There can be glare and haloes, or a feeling of blurred vision after surgery as well as pain or discomfort; this may sometimes occur in an apparently otherwise healthy eye and there is not always a clear explanation as to why.
  • Distortion of the pupil so that it may not be the same size as the other eye or may not be round.
  • Double vision or, rarely, difficulty keeping the eyes aligned. Complications are rare and in most cases can be treated effectively. In small proportion of cases, further surgery may be needed. Very rarely some complications can result in blindness.
  • The most common complication is called “Posterior capsular opacification It may come on gradually after months or years.
    When this happens, the back part of the lens capsule, which was left in the eye to support the implant, becomes cloudy.