Cataract Surgery




Cataract surgery involves replacing the cloudy lens inside your eye with an artificial one.

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

It can take 4 to 6 weeks to fully recover from cataract surgery.

What are cataracts?

Cataracts are when the lens of your eye, a small transparent disc, develops cloudy patches.

When we're young, our lenses are usually like clear glass, allowing us to see through them.

As we get older they start to become frosted, like bathroom glass, and begin to limit our vision.

Cataracts most commonly affect adults as a result of ageing. See age-related cataracts.

Do you need surgery?

If you have cataracts, it's your decision whether or not to go ahead with cataract surgery.

Cataracts usually get slowly worse over time. Surgery to replace the cloudy lens is the only way to improve your eyesight.

Surgery is usually offered on the NHS if your cataracts are affecting your eyesight and quality of life.

The decision to have surgery should not be based solely on your eye test (visual acuity) results.

You may have other personal reasons for deciding to have surgery, such as your daily activities, hobbies and interests.

You can choose to put off having surgery for a while and have regular check-ups to monitor the situation.

There are no medicines or eye drops that have been proven to improve cataracts or stop them getting worse.

Before the operation

Before surgery, you'll be referred to a specialist eye doctor for an assessment.

During the assessment different measurements will be taken of your eyes and your eyesight.

The assessment is an opportunity to discuss anything to do with your operation, including:

  • your lens preference, such as near sight or long sight
  • the risks and benefits of surgery
  • if you'll need glasses after surgery
  • how long you'll take to fully recover

If you're used to using one eye for distance and one for reading, which is called monovision, you can ask to stay that way.

This usually means you'll get a near sight lens fitted in one eye and a long sighted lens fitted in the other eye.

The operation

Cataract surgery is a straightforward procedure that usually takes 30 to 45 minutes.

It's often carried out as day surgery under local anaesthetic and you should be able to go home on the same day.

During the operation, the surgeon will make a tiny cut in your eye to remove the cloudy lens and replace it with a clear plastic one.

With the NHS, you will usually be offered 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.

If you go private, you may be able to choose either a multifocal or an accommodating lens, which allow the eye to focus on both near and distant objects.

Most people will need to wear glasses for some tasks, like reading, after surgery regardless of the type of lens they have fitted.

If you have cataracts in both eyes, you'll need two separate operations, usually carried out 6 to 12 weeks apart.

This will give the first eye to be treated time to heal and your vision time to return.

Find out more about recovering from cataract surgery.

Benefits of surgery

After cataract surgery you should be able to:

  • see things in focus
  • look into bright lights and not see as much glare
  • tell the difference between colours

If you have another condition affecting your eyes, such as diabetes or glaucoma, you may still have limited vision, even after successful surgery.

Risks of surgery

The risk of serious complications developing as a result of cataract surgery is very low.

Most common complications can be treated with medicines or further surgery.

There is a very small risk - around 1 in 1,000 - of permanent sight loss in the treated eye as a direct result of the operation.

When cataract surgery is offered

When cataract surgery is offered

Cataract surgery is usually offered on the NHS if you have cataracts that are affecting your ability to carry out daily activities.

For example, surgery may be offered if problems with your vision are causing difficulties reading, driving, or looking after someone in your care.

In the past, people with cataracts were encouraged to wait until they could hardly see. However, these days surgery to remove a cataract can be carried out at any stage once your sight has been affected.

There are no national guidelines stating what your level of vision needs to be before cataract surgery is carried out, although individual NHS clinical commissioning groups (CCGs) may have their own criteria outlining when cataract surgery should be offered.

In some cases, cataract surgery may be recommended if you have another eye condition, such as diabetic retinopathy, that can't be monitored or treated properly if you have cataracts.

Waiting to have surgery

Cataracts tend to get gradually worse over time, although it isn't possible to predict how quickly this will happen.

Most people with cataracts will need surgery eventually, but immediate treatment may not be necessary if your vision isn't significantly affected.

It doesn't become more difficult to remove a cataract if you decide to wait before having surgery.

If immediate treatment isn't necessary or you decide to wait before having surgery, other measures may be helpful in the meantime, such as:

  • new glasses
  • brighter lighting
  • anti-glare sunglasses
  • magnifying lenses

There are no medications, eye drops, or dietary supplements that have been proven to improve cataracts or stop them getting worse.

How cataract surgery is performed

How cataract surgery is performed

Before having cataract surgery, you'll be referred to a specialist eye doctor (an ophthalmologist or ophthalmic surgeon) for an assessment.

The specialist will assess your eyes and general health, and check for any other eye conditions that may be affecting your vision.

A member of the eye care team will take measurements of your eyes to assess the strength of the artificial lens that will replace your natural lens.

This is also a good time to discuss the procedure in detail and ask any questions you may have.

If you have cataracts that affect your vision in both eyes, you'll need two separate operations, usually carried out 6 to 12 weeks apart.

This will give the first eye that's been treated time to heal and your vision time to return. It also allows the surgeon to know your new glasses prescription in the first eye.

The procedure

Cataract surgery is a common and relatively straightforward procedure that usually takes up to 30 to 45 minutes.

It's usually carried out as day surgery under local anaesthetic, which means you're conscious during the procedure and can go home on the same day.

The most common surgical technique used is known as phacoemulsification.

Before the operation, a nurse will put drops in your eye to widen (dilate) your pupil.

You'll also be given a local anaesthetic, which can be applied as eye drops or given as an injection into the tissue around your eye.

The surgeon will make a tiny cut in your cornea, the transparent layer of tissue at the front of your eye.

A small probe that emits ultrasound waves is inserted through your cornea into the eye to break the affected lens into pieces. The pieces are then liquified and sucked out. A second probe sucks out the remaining soft pieces of outer lens.

After the affected lens has been removed, the surgeon will insert a small plastic lens in its place.

The replacement lens is usually curled up in an injector and injected through the cut in the cornea. When it's in place, it unfolds itself and adopts the natural position of the old lens.

In a few cases, it may be necessary to make a slightly larger incision in the eye to replace the affected lens, which may need to be closed with tiny stitches that are removed a few weeks later. 

Replacement lenses

After the cloudy lens has been removed, it will be replaced with an artificial clear plastic lens. The replacement lens is called an intraocular implant, or intraocular lens (IOL).

There are three types of IOL available. They are:

  • fixed strength (monofocal) lenses - which are set for one level of vision, usually distance vision; this type of lens is used in the majority of cataract operations
  • multifocal lenses - which can be set at 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 a natural lens

Using multifocal or accommodating lenses can potentially reduce the chances of needing reading glasses after surgery, although most people will need to wear glasses in some situations after surgery regardless of the type of lenses they had fitted.

Multifocal and accommodating lenses aren't usually available on the NHS. If you would like multifocal or accommodating lenses, you may be able to have them by paying for cataract surgery privately.

After surgery

Most people are able to go home a few hours after having cataract surgery, although you'll need to arrange for someone to collect you and take you home. You'll usually have a pad over your eye when you go home.

It's also a good idea to arrange for someone to help look after you when you get home as you may feel out of sorts for 24 hours.

If the vision in your other eye is poor, you may struggle with your vision for the first few days as it settles down.

It's likely you'll experience some discomfort in and around your eye after the procedure, but this should improve within a few days.

Complications in the days and weeks after surgery are rare, but you should contact the hospital as soon as possible if you experience increasing pain or vision loss at any point.

Read more about recovering from cataract surgery and the risks of cataract surgery.

Recovering from cataract surgery

Recovering from cataract surgery

You should be able to go home on the same day as your cataract surgery.

You may have a pad and plastic shield over your eye when you leave hospital, which can usually be removed the day after surgery.

Feeling should start to return to your eye within a few hours of surgery, but it may take a few days for your vision to fully return.

It's normal to have:

  • grittiness
  • watering
  • blurred vision
  • double vision
  • red or bloodshot eye

These side effects usually improve within a few days but it can take 4 to 6 weeks to recover fully.

If you need new glasses, you won't be able to order them until your eye has completely healed - usually after 6 weeks.

Cataract surgery has a high success rate in improving your eyesight and should allow you to return to your normal activities, like driving.

When to seek help

Contact your eye surgery department as soon as possible if you experience:

  • increased pain and/or redness
  • increased stickiness
  • decreased vision

Dos and don'ts

For the first few weeks after surgery:


  • use your eye drops as instructed
  • take it easy for the first 2 to 3 days
  • use your eye shield at night for at least a week
  • take painkillers if you need to
  • bathe or shower yourself as usual
  • wear your eye shield when washing your hair
  • read, watch TV and use a computer
  • use your shield, old glasses or sunglasses outdoors
  • avoid swimming for 4 to 6 weeks


  • rub your eye
  • allow soap or shampoo to get into your eye
  • drive until you get the all-clear from your doctor
  • do any strenuous exercise or housework
  • wear eye make-up for at least 4 weeks
  • fly without seeking advice from your doctor

You could arrange for someone to help take care of you until your vision returns, particularly if the vision in your other eye is poor.

If you work, how soon you can return will largely depend on your type of job and if you need new glasses.

Using your eye drops

Before you leave hospital, you'll be given some eye drops to help your eye heal and prevent infection.

It's important to use your eye drops as instructed by your doctor. Unless told otherwise, you should:

  • start your drops the morning after the operation
  • only use them on the operated eye
  • wash your hands before using your drops
  • don't stop your eye drops without advice from your doctor
  • don't let anyone else use your eye drops

You'll be advised further about the use of eye drops at your follow up appointment, usually 1 to 4 weeks after your operation.

At this appointment, you may be given advice on when to stop using your eye drops and when to apply for new glasses.

How to apply eye drops

  1. wash your hands
  2. tilt your head back
  3. look up at the ceiling
  4. gently pull down the lower lid
  5. squeeze the bottle until a drop goes into your eye
  6. close your eye and wipe away any excess liquid
  7. don't let the bottle touch the eye

If you run out of the drops, contact your local GP for more. You'll need to bring your eye drop bottle and discharge letter to your appointment.

How to clean your eye

  • boil some water and allow it to cool
  • wash your hands
  • dip cotton wool or clean gauze in the cool boiled water
  • gently wipe from the inside (near your nose) to the outside corner of your eye
  • don't wipe inside your eye
  • don't wash your eye out with water
  • don't press on your eye

During the first 2 weeks, you may need to clean your eye twice a day because the drops and the healing process can cause slight stickiness.

For more on cataracts go to the RNIB website.

Risks of cataract surgery

Risks of cataract surgery

The risk of serious complications developing as a result of cataract surgery is very low. Most common complications are treatable and don't have a long-term impact on your vision.

The risk of complications is higher in people with other eye conditions, such as uveitis, severe short-sightedness (high myopia) or diabetic retinopathy.

The risk of complications is also higher if you can't lie flat easily, have problems breathing, or are taking tablets for prostate problems.

Ask your eye surgeon (ophthalmologist) to explain the possible risks before the operation.

Cloudy vision

The main problem that can occur after cataract surgery is a condition called posterior capsule opacification (PCO).

This is where part of the lens capsule - the "pocket" the lens sits inside - thickens, which can cause cloudy vision. This isn't the cataract returning, but a skin or membrane growing over the back of the artificial lens.

Less than 10% of people who have cataract surgery will eventually develop PCO, usually within two years.

If you develop PCO and your vision is affected, you may need laser eye surgery to correct it. During this procedure, the cloudy part of the lens capsule will be removed, leaving enough of the capsule to hold the artificial lens in place.

Laser eye surgery for PCO is a short and relatively simple procedure that usually takes about 15 minutes.

Your vision should either be improved immediately or within a few days and, as no surgical incisions or stitches are necessary, you should be able to return to your normal activities straight away.

Other complications

Other complications of cataract surgery are much less common, but can include those listed below. 

During the operation:

  • inability to remove all of the cataract
  • tearing of the lens capsule
  • bleeding inside the eye
  • a bit of the cataract dropping into the back of the eye
  • damage to other parts of the eye, such as the transparent outer layer of the eye (cornea)

After the operation:

  • swelling and redness (inflammation) in the eye
  • swelling of the retina (cystoid macular oedema) - where fluid builds up between layers of the retina at the back of the eye, sometimes affecting vision
  • swelling of the cornea - where fluid builds up in the cornea at the front of the eye; this usually clears itself
  • retinal detachment - a rare complication where the retina (the layer of nerve cells inside the back of the eye) becomes separated from the inner wall of the eye
  • infection in the eye - such as endophthalmitis (a rare bacterial infection)

You should seek immediate medical advice if you experience any loss of vision or increasing pain or redness after cataract surgery.

It's usually possible to successfully treat complications that arise from cataract surgery with medication or further surgery.

Rarely, your vision may be worse than it was before surgery. There's also a very small risk - around 1 in 1,000 - of permanent damage to your eye, causing a loss of sight.

However, the majority of people have a good result from surgery and are happy with the improvement in their vision.

'My eyesight is incredible. I can see brilliant colours again'

'My eyesight is incredible. I can see brilliant colours again'

Brenda Alworth had two cataract operations, with the second four years after the first.

"My eyesight was so blurry I couldn't see across the room. When I went to my optician, he said I had a cataract in my right eye. He said he could see the beginnings of one in my left eye, but that I could leave that one alone for the time being.

"The first operation was a great success and I started to see much more clearly again, but then gradually my sight started to get blurry in my left eye, so my optician said I should have a second operation.

"I was referred to Stoke Mandeville Hospital, where a nice nurse and surgeon examined my eyes and measured me up for my lens. I'm long-sighted, so I still have to wear glasses for reading and close work.

"I was terrified on the day of the operation, but my son came with me and the nurses were incredibly kind and looked after me all the time. I'd had a local anaesthetic when my first cataract was removed, but this time they just used anaesthetic drops. I didn't feel anything, and all I was aware of was a bright light as the surgeon got down to work.

"The nurse put a pillow under my legs to make sure I was comfortable and she held my hand throughout the operation. She told me I could give it a squeeze if I started to feel uncomfortable at any time and the surgeon would stop.

"It was very quick. I was only in the theatre for 15 minutes and was able to go home shortly afterwards. My eye was covered with a plastic eye patch, which I was able to take off the day after the operation. I had the operation on the Friday and was back at work on the Monday.

"My eye felt a bit dry for the first few days, but my sight gradually got better. It's fantastic now and I can see colours again - brilliant whites and bright blues. It's incredible and I have had no side effects.

"I did ask the surgeon if my eyes could go cloudy again. He said there was a very small chance, but that a five-minute operation with a laser would soon sort it out."