What is it?

Just behind the iris (the coloured part of the eye) is the lens. The lens helps focus light onto the retina (the light-sensitive layer at the back of the eye).

Lenses need to be clear (transparent) to let the light pass through. A cataract is the name for a lens that has become cloudy.

Cataract is a major cause of sight loss, as it affects approximately 380,000 people in the UK. Approximately 390,000 cataract surgeries are carried out each year in England and 16,000 in Wales.

  • What are the causes of cataract?

    Cataract is a common condition most often seen in older age as part of the normal ageing process, but can happen at any age. Some rare inherited conditions mean that babies will be born with cataract.

    Cataracts develops due to the proteins of the lens changing their arrangement and clumping together which causes the clear lens to become cloudy, which means light is unable to pass through it directly.

    Other causes of cataract include diabetes, eye injury and use of steroid eye drops or tablets. Cataract is also often seen together with other eye conditions.

  • What are the symptoms of cataracts

    Cataract causes blurred or hazy vision, which may appear ‘washed out’, with less contrast between black and white. Bright lights such as car headlamps might cause glare or dazzle, especially at night. Colours can also seem altered or more yellow.

    As cataract can affect each eye differently, some people will notice different vision in one eye compared to the other.

    Cataracts gradually get worse over time. Sometimes progression happens so slowly that the person with cataract doesn’t notice the sight loss.

    Cataract is not painful but can cause blindness if left untreated.

  • Cataracts treatment

    Cataract surgery is very successful and serious complications are rare.

    At the moment, cataract can only be treated with surgery. It is the most common operation in the developed world.

    This very delicate operation involves removing the cloudy human lens and replacing it with a new artificial plastic lens.

    In the UK, most people who have the operation are in their mid-70s. It takes about 30 minutes and is usually done under local anaesthetic as a day case.

    Cataract surgery is very successful and serious complications are rare.

  • How can cataract be prevented?

    Cataract cannot be treated, slowed down or prevented with medicine or eye drops.

    Watching TV or computers does not cause cataracts. Some population studies suggest that stopping smoking and wearing sunglasses with UV protection may help prevent cataract or slow down its progress. But there is no evidence that these, vitamins, diets or changes in life style are of benefit to individual people.

  • Latest research on cataracts

    Key topics in cataract research include developing a non-surgical treatment for preventing or delaying cataract and preventing a common complication of cataract surgery called ‘posterior capsule opacification’ in which the natural membrane situated directly behind the artificial lens clouds over and needs treatment to clear it again.

    Read our research projects
  • Cataract personal stories

    Mother and daughter, Joy and Hazel, were both born with congenital cataracts a condition that has affected three generations of their family.

    Joy’s mother lived with the condition, which was passed onto Joy, who then passed the gene onto her two daughters, Hazel and Melissa.

    Joy,  received ten operations when she was younger and was also diagnosed with nystagmus. When aged 31 she was diagnosed with glaucoma and at the age of 48 received her first corneal graft and this procedure was repeated six years later. This has had a huge impact on Joy’s vision – she has about three per cent of her vision remaining and is now registered blind.

    Her oldest daughter, Hazel, was born in 1978 and shortly afterwards was diagnosed with the condition. She had corrective surgery when she was just a few months old.

    Joy said: “I can remember me and my husband coming out of the doctors in floods of tears after we received Hazel’s diagnosis. No one likes to see their children in pain.”

    Hazel also developed a slight nystagmus and has about ten per cent of her sight remaining. Hazel went on to have two children, William, aged 10 and Andrew, 7.

    Hazel started to notice that something was wrong with Andrew’s sight when he was six weeks old. She said: “A mum just knows when something isn’t quite right. I flagged this during Andrew’s eight week check-up and following tests, the GP confirmed that the cataracts were there.”

    Following this Andrew also went through a corrective procedure and thankfully because of advances in science and research – the operation proved successful.

    Hazel said: “Taking your baby to hospital and sitting there with an anaesthetist putting them to sleep - is heartbreaking. I’m just so pleased that Andrew’s outcome has been so much better than mine.

    “Eye research is really important to me, so I support Fight for Sight because it’s enabling more medical research to take place. My hope is that medical research will continue to improve from generation to generation.”

  • Cataract clinical trials

    You could play an important part in eye research by being a participant in clinical research study that may benefit many people. You could even help shape clinical research by becoming more actively involved and having a say. Patients, carer, or anyone with an interest can help.

    What are clinical trials

    Clinical trials are research studies that find out if a medical strategy, treatment, or device is safe and effective for humans. They are a key research tool for improving medical knowledge and patient care. The people who carry out research are mostly the same doctors and healthcare professionals who treat people. Their aim is to find better ways of treating patients and keeping people healthy.

    Taking part

    Here are some ways to find out about research projects and clinical trials that you can get involved in.

    UK Clinical Trials Gateway

    The UK Clinical Trials Gateway run by the National Institute for Health Research (NIHR) provides easy to understand information about clinical research trials running in the UK, and gives to a large range of information about these trials. It is designed to enable patients and clinicians to locate and contact trials of interest. Visit their website and select the eye condition that you are interested in.

    NIHR Clinical Research Network Portfolio

    The NIHR Clinical Research Network Portfolio is a database of high-quality clinical research studies in England, Northern Ireland, Scotland and Wales. Within this the Ophthalmology Specialty Group supports a national portfolio of research studies in ophthalmology and the vision sciences. See their website for details.

    If you wish to join a trial it is always best to discuss this with your doctor or clinical team first.

Last updated October 2017
Approved by Mr Frank Larkin, Moorfields Eye Hospital 

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