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A cataract is a clouding of the lens inside your eye. Developing cataracts will cause your sight to become cloudy and misty. Cataracts are treated by surgery, during which the cloudy lens is removed and replaced by an artificial lens.

This page contains a summary of our information on cataracts. To read our full information, download our Understanding cataracts booklet, which is accredited by the Royal College of Ophthalmologists:

Do I have cataracts?

Cataracts normally develop very slowly. At first, the changes they make to your sight may be difficult to notice, but as they get worse, you’ll start to notice symptoms such as:

  • You feel like your glasses are dirty and need cleaning, even when they don’t.
  • Your sight is misty and cloudy.
  • You’re more sensitive to light – bright sunlight or car headlamps may glare more.
  • Everything looks a little more washed out than it should be.

Eventually, almost all people with cataracts will find that their sight has turned misty or cloudy, and things have become difficult to see all the time. Cataracts sometimes develop so slowly that you might not notice any changes in your vision, but when you have your regular eye test, your optometrist (optician) may detect them.

Why have I developed cataracts?

Developing cataracts is a normal part of growing older. Most people start to develop cataracts after the age of 65, but some people in their forties and fifties can also develop cataracts.

Certain things make it more likely that you will develop cataracts:

  • Diabetes – people who have diabetes often develop cataracts earlier.
  • Trauma – having an eye injury can cause the injured eye to develop a cataract.
  • Medications – some prescription drugs can cause cataracts, for example steroids.
  • Eye surgery – surgery for a retinal problem will likely lead to cataracts in the affected eye at some point in the future.
  • Eye conditions – other eye conditions, such as retinitis pigmentosa, glaucoma or uveitis, may also cause cataracts.
  • Having high myopia (being very short sighted) may cause cataracts.

Despite the different causes, most cataracts are dealt with using the same type of surgery. Some children have cataracts (also known as childhood cataracts) which are dealt with in a different way.

What can be done about cataracts?

Cataracts can be removed by surgery. Cataract surgery removes your cloudy lens and replaces it with an artificial lens. This lens is known as an intra-ocular lens implant – often shortened to IOL. The artificial lens is made of plastic or silicone and will not need to be changed for the rest of your life.

There isn’t any medicine or drops that can remove cataracts – surgery is the only way to treat them. Unfortunately, there’s nothing you can do to stop cataracts from developing or getting worse, however it’s a good idea to wear sunglasses to protect your eyes from ultraviolet (UV) light.

Normally, if you have cataracts in both eyes, they will be removed separately. You’ll usually have one eye operated on first and then once this eye is healed, you’ll have the cataract in your other eye removed a few weeks or months later.

An ophthalmologist may consider removing both cataracts at the same time for people who are at low risk of ocular complications during and after surgery, or people who need to have general anaesthesia for cataract surgery but for whom general anaesthesia carries an increased risk of complications or distress.

When should I have cataract surgery?

Cataracts can be removed at any stage. You don’t have to wait for them to “ripen” before having surgery.

Making the decision to have your cataracts removed depends on several things:

The decision to have your cataracts removed comes down to whether the benefit of having the operation outweighs the small risk attached to the surgery.

If you have no other eye conditions or health concerns, then the benefit of having your cataracts removed usually outweighs the risk of surgery. For example, if you’re finding it difficult to read, use a computer or drive, then removing your cataracts may be necessary.

The timing of surgery is different for everyone. If you make your living by driving, for example, you may need your cataracts removed earlier than someone who doesn’t drive.

If you have another eye condition, it may be possible to have your cataracts removed, but there may be more concerns about complications. Your ophthalmologist (hospital eye doctor) may want to delay the operation for as long as possible to put off the risk of the surgery, but this needs to be balanced with how much of your sight is being affected by cataracts.

If you have sight in only one eye, your ophthalmologist may recommend putting off surgery for as long as possible. Having sight in only one eye doesn’t make the cataract surgery more difficult, but any serious complication which affects your sight would mean the outcome is worse when compared to someone with sight in both eyes. By delaying the operation for as long as possible, this risk is avoided until the operation is necessary.

Once you are offered surgery for your cataracts, it’s your decision when to have your cataracts treated. Cataracts only affect the lens and no other part of your eye. If you decide to put off surgery, your sight will become increasingly cloudy, but the results of your surgery, no matter how delayed, will be the same as if you had it done earlier. You don’t have to worry that you’re permanently damaging your vision by delaying surgery.

Some people have cataracts removed when their vision isn’t necessarily adversely affected by the presence of cataract, but to help with other eye conditions or monitoring of other eye conditions.

We also have an advice page for anyone waiting for Cataract surgery.

Cloudy sight after cataract surgery – what is posterior capsule opacification?

During cataract surgery, a clear artificial lens is placed inside your lens capsule, the membrane that originally covers your natural lens. Your lens capsule is clear and remains clear following your cataract surgery.

Posterior capsule opacification (PCO) is a common complication that can occur sometime after cataract surgery. It is estimated to occur in roughly one in five eyes that have cataract surgery. People develop PCO months to years after having cataract surgery.

PCO occurs because cells remaining after cataract surgery grow over the back (posterior) of the capsule causing it to thicken and become slightly opaque (cloudy). This means that light is less able to travel through to the retina at the back of your eye. As a result, your sight can become blurred and cloudy, or you may have problems with bright lights and glare.

PCO can be easily treated with a quick, painless, outpatient laser procedure known as YAG (Yttrium Aluminium Garnet) laser surgery, to make vision clear again. The laser treatment removes some of the thickened and cloudy lens capsule to make sight clear again.

Once you have had the YAG laser treatment, PCO doesn’t normally cause any long-term problems with your sight.

Read more about PCO and the laser surgery used to treat it.

Watch our what to expect during cataract surgery story

Further information and support

If you have any questions about cataracts, cataract surgery or PCO, we're here for you. Just get in touch with our Sight Loss Advice Service.

NHS Choices has information and advice on age-related cataracts and cataract surgery.

Page last reviewed: Feb. 10, 2023

Next review due: April 17, 2024