Cataract surgery

Cataract surgery


Cataract surgery is a procedure used to treat cataracts that are affecting your daily activities.

It is the most common operation performed in the UK, with more than 300,000 procedures carried out each year.

What are cataracts?

cataract is cloudiness of the lens (the normally clear structure in your eye which focuses the light). They can develop in one or both eyes.

The cloudiness can become worse over time, causing vision to become increasingly blurry, hazy or cloudy.

Most cataracts develop with age, although rarely babies are born with cataracts or children develop them while they are still young.

Read more about childhood cataracts or treating childhood cataracts.

These pages are about surgery for adults with cataracts.

When is cataract surgery recommended?

Minor cloudiness of the lens is a normal part of ageing. Significant cloudiness, or cataracts, generally get slowly worse over time and surgery to remove them is the only way to restore vision.

However, it’s not necessary to have surgery if your vision is not significantly affected and you don’t have any difficulties carrying out everyday tasks.

Cataract surgery is available on the NHS if they are making it difficult to carry out activities such as reading, driving and looking after someone under your care.

Read about when cataract surgery is carried out.

The operation

Cataract surgery is a relatively straightforward procedure that normally takes up to 30 to 45 minutes.

It is usually carried out as day surgery under local anaesthetic, which means you are awake during the procedure and you can go home on the same day.

During the operation, the surgeon makes a tiny incision (cut) in your eye so they can remove the affected lens. When the lens has been removed, the surgeon inserts a small plastic lens, called an intraocular implant or intraocular lens, in its place.

If you have cataracts in both eyes, this procedure will usually be carried out on separate occasions a few weeks apart. This gives the first eye time to heal and time for your vision to return.

Read more about how cataract surgery is performed.

Getting back to normal

You will normally be able to go home a few hours after having cataract surgery, although you will need to arrange for someone to collect you and take you home.

Take it easy for the first two or three days after the operation and make sure to use any eye drops you are given by the hospital.

You can carry on with most of your normal activities after cataract surgery, although you will need to avoid touching your eye or getting anything in it (such as soap and water) for a few weeks.

Read more about recovering from cataract surgery.

Results of cataract surgery

Most people will experience an improvement in their sight soon after cataract surgery, although your vision may be blurred for a few days.

Eventually, you will usually be able to:

  • see things in focus (although glasses are often needed)
  • look into lights without as much glare
  • tell the difference between colours, which will seem brighter

Most people need to wear glasses for near or distance vision (or both) after cataract surgery. This is because artificial lens implants cannot focus on a range of different distances.

Normally, the surgeon will aim for more focused distance vision, with dependence on reading glasses for close up work, although this depends on the strength of your glasses and individual circumstances.

With glasses, most people have a good enough level of vision to be able to drive and carry out everyday activities without difficulty.

Your vision may not be restored to normal if you also have another eye condition or in the rare event of a serious complication.

What are the risks?

The risk of serious complications as a result of cataract surgery is small.

The most common complication is a condition called posterior capsule opacification (PCO), which can cause your vision to become cloudy again. This is where a skin or membrane grows over the back of the lens implant months or years later.

If necessary, PCO can be treated with a simple laser eye surgery procedure to cut away the membrane.

Other complications are much rarer and can include:

  • tearing of the lens capsule (the “pocket” that holds the lens in place)
  • all or a bit of the cataract dropping into the back of the eye
  • inability to remove all of the cataract or insert a lens implant
  • infection or bleeding in the eye

Most complications that can potentially develop after cataract surgery can be treated with medication or further surgery, and don’t usually have a long-term impact on your vision. However, there is a very small risk (around one in 1,000) of permanent loss of sight in the treated eye as a direct result of the operation.

Read more about the risks of cataract surgery.

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 under your care.

In the past, people with cataracts were encouraged to wait until they could hardly see. These days, surgery to remove a cataract can be done at any stage once your ability to function is 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 that cannot be monitored or treated properly while you have cataracts, such as diabetic retinopathy.

Waiting to have surgery

Cataracts tend to get gradually worse over time, although it is not possible to predict how quickly this will happen.

Most people will need surgery eventually, but immediate treatment may not be necessary if your vision is not significantly affected.

It does not 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

Before having cataract surgery, you will 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 particularly 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.

If you have cataracts affecting vision in both eyes, surgery will normally be carried out on two separate occasions, usually 6 to 12 weeks apart.

This gives the first eye 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 normally takes up to 30 to 45 minutes. It is usually carried out as day surgery under local anaesthetic, which means you are awake during the procedure and you 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 dilate (widen) your pupil. A local anaesthetic will also be given, which can be applied as eye drops or given as an injection into the tissue around the eye.

The surgeon then makes a tiny cut in your cornea (the transparent layer at the front of your eye). A small probe that emits ultrasound waves (high-frequency sound waves) is inserted through your cornea into the eye to break the affected lens into pieces. These pieces are then liquified and sucked out. A second probe sucks out the remaining soft pieces of outer lens.

When the affected lens has been removed, the surgeon inserts 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 is 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

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

There are three types of IOL available:

  • fixed strength (monofocal) lenses, which are set for one level of vision, usually distance vision – these are used in the vast 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 are also not usually available on the NHS. Ask your ophthalmologist about the type of lenses available in your area before having surgery. If NHS funding is not available for the type of lens you want, you may be able to have it by paying for the cataract surgery privately.

After surgery

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

It is 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 will 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

You can usually go home on the same day you have cataract surgery, although you will need to arrange for someone to collect you and take you home.

You will normally have a pad and plastic shield over your eye when you leave hospital. This can usually be removed the following day, although you may be advised to wear the shield at night for a week or two. This is to prevent you rubbing or pushing your eye when you are asleep.

You should start to get feeling back in your eye within a few hours of surgery, although it may take a few days for your vision to fully return. If possible, you may find it useful to arrange for someone to help take care of you until your vision returns, particularly if the vision in your other eye is poor.


Before leaving hospital, you will be given a 24-hour phone number to call if you have any problems. You will also be given some drops you need to use for the next four weeks to help the eye heal and prevent infection. You will also be told when to return for a follow-up appointment.

The follow-up appointment will usually take place at some point between two and six weeks after the operation. During this appointment, an eye care professional will check your eye and you will be told when you can stop using the eye drops.

If you need new glasses, you will be told when you should visit an optometrist (optician) to have your eyes tested and glasses fitted. In most cases, you will have to wait several weeks for your vision to settle down before an optometrist can give you a new glasses prescription.

Recovering at home 

You should try to take it easy for the first two or three days after cataract surgery. Continue to use the eye drops that you have been given until you are advised that you can stop. These are usually needed for a few weeks.

You will probably experience some side effects after surgery, such as:

  • mild pain in and around the eye
  • an itchy or sticky eye
  • blurred vision
  • a feeling of grittiness in the eye
  • a slight headache
  • bruising of the skin around the eye
  • discomfort when looking at bright lights

However, these side effects are completely normal and should improve in a few days.

You can take an over-the-counter painkiller, such as paracetamol, if you experience any pain. Wearing sunglasses may help avoid reduce any short-term discomfort caused by bright lights.

When to seek medical advice

Contact the hospital where the operation was carried out for advice as soon as possible if you experience:

  • severe or increasing pain
  • worsening or loss of vision
  • increasing redness in the treated eye
  • the sudden appearance of floaters (black dots, specks or streaks in your field of vision) or flashes of light in the treated eye

These problems may be a sign of a complication of cataract surgery.


Your surgeon will advise you about any activities you need to avoid while recovering from your operation.

In many cases, you will be allowed to bend over, carry shopping, wash your face and hair, and generally carry on with life as normal. However, you should:

  • try not to touch or rub your eye
  • keep soap and shampoo out of your eyes
  • avoid wearing eye make-up for one week
  • avoid swimming for two to four weeks
  • avoid sports and activities where there is a risk that you may get knocked in the eye for two to four weeks

You can read and watch television almost immediately without doing any harm, although your vision may be blurry until your eye gets used to its new lens or you have new glasses fitted.

If you work, how soon you can return will largely depend on what your job involves. Most people can return after a few days, but you may need a few weeks off if your job involves strenuous activities or potential exposure to liquid or dust that could get into your eye.


Up to 90% of people who have surgery for cataracts will eventually have a good enough level of vision to start driving again if they have no other eye condition.

The Driver and Vehicle Licensing Agency (DVLA) states that you can start driving again if you can read a number plate 20 metres away with both eyes open. Many people who have cataract surgery will need glasses to be able to do this, in which case you will need to wait until your new glasses are fitted a few weeks after surgery.

If your vision is good in the other eye, you may be able to do this sooner, but in either case you also need to be confident doing an emergency stop.

Wearing glasses after cataract surgery

Most people will need to wear glasses for either long or short distance vision after cataract surgery, even if they didn’t need to before the operation. This is because artificial lens implants cannot focus on a range of different distances.

Natural lenses can do this in people under 50 years of age, but this ability is gradually lost with age, so most people require reading glasses before surgery anyway.

A review of a number of studies found that 95% of people with a monofocal lens and about 70% of people with a multifocal lens needed glasses after having cataract surgery.

Another type of artificial lens, called an accommodating lens, is designed to act in a more similar way to a natural lens. This should allow for a better range of focus after cataract surgery. 

However, while there is evidence these lenses improve the range of focus, the National Institute for Health and Care Excellence (NICE) says more evidence is needed to be sure these lenses improve accommodation (how the lens adapts to focus images) before they are made routinely available on the NHS.

Read the NICE guidance on the use of accommodating lenses and multifocal lenses.

Risks of cataract surgery

The risk of serious complications 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, high myopia (severe short-sightedness) or diabetic retinopathy.

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

Ask your eye surgeon (ophthalmologist) to explain the possible risks before your 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” that the lens sits inside) thickens, which can cause cloudy vision. This is not 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 (when laser light is used to cut through the membrane) 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 normally 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 cornea (the transparent outer layer of the eye)

After the operation:

  • inflammation (swelling and redness) 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 (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 is 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 and there is also a very small risk (around one in 1,000) of permanent damage to your eye, causing a loss of sight.

However, the vast 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’

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 nice 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 is 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.”