Cataract surgery is a procedure used to treat cataracts, where changes in the lens of the eye cause cloudy, blurry, or misty vision.
It's the most common operation performed in the UK, with more than 300,000 procedures carried out each year.
Cataracts occur when changes in the lens of the eye cause it to become less transparent. The lens is the crystalline structure that sits just behind your pupil, which is the black circle in the centre of your eye.
When light enters your eye, it passes through the transparent layer of tissue at the front of the eye (the cornea) and the lens, which focuses it on the light-sensitive layer of cells at the back of your eye (the retina).
Cataracts sometimes start to develop in a person's lens as they get older (age-related cataracts), stopping some of the light reaching the retina. This can affect your vision, making it become increasingly cloudy, blurry, or misty.
Although cataracts are often associated with age, in rare cases babies are born with cataracts or young children can develop them (childhood cataracts).
This topic focuses on surgery for adults with cataracts.
When is cataract surgery recommended?
Slight cloudiness of the lens is a normal part of ageing. Significant cloudiness, or cataracts, usually get slowly worse over time. Surgery to remove them is the only way to restore vision.
However, surgery isn't necessary if your vision isn't significantly affected and you don't have difficulties carrying out everyday tasks.
Cataract surgery is available on the NHS if you're having difficulty with activities such as reading, driving, or looking after someone in your care.
Read more about when cataract surgery is carried out.
Cataract surgery is a relatively straightforward procedure that usually takes 30 to 45 minutes.
It's often carried out as day surgery under local anaesthetic, which means you'll be awake during the procedure and can go home on the same day.
During the operation, the surgeon will make a tiny cut (incision) in your eye so they can remove the affected lens. After it's been removed, a small plastic lens called an intraocular implant or intraocular lens will be inserted.
If you have cataracts in both eyes, you'll have two separate operations carried out 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'll normally be able to go home a few hours after having cataract surgery, but you'll 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 you use any eye drops you're given while in hospital.
You can continue doing most of your normal activities after cataract surgery, although you'll 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's sight will improve soon after having cataract surgery, although your vision may be blurred for a few days.
Eventually, you should be able to:
- see things in focus, although glasses are often needed
- look towards 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 can't focus on a range of different distances.
The surgeon will normally 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 any problems.
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 and complications?
The risk of serious complications developing 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. In PCO, 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 risks or complications of cataract surgery are much rarer and can include:
- tearing of the lens capsule, the "pocket" that holds the lens in place
- all or some 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's a very small risk – around 1 in 1,000 – of permanent sight loss in the treated eye as a direct result of the operation.
Read more about the risks of cataract surgery.