There are a number of different reasons why a child may be born with cataracts or develop them while they are still young, although it is not possible to determine the exact cause in many cases.

Some of the main causes of childhood cataracts are described below.

Genes and genetic conditions

Cataracts present from birth (congenital cataracts) are sometimes caused by a faulty gene being passed to a child from their parents. This fault means that the lens does not develop properly.

It’s estimated that there is a family history of congenital cataracts in around one in every five cases of the condition.

Cataracts can also be associated with conditions caused by chromosome abnormalities, such as Down’s syndrome. Chromosomes are the parts of the body’s cells that carry the genes.

Infections in pregnancy

Congenital cataracts can also be caused by infections caught by the mother during pregnancy. The main infections linked to an increased risk of congenital cataracts include:

• rubella (German measles) – a viral infection that can cause a red-pink spotty skin rash
• toxoplasmosis – a parasitic infection caught by consuming food, water or soil contaminated with an infected cat’s faeces
• cytomegalovirus (CMV) – a common virus that usually causes few symptoms
• chickenpox – a mild but highly infectious condition caused by the varicella-zoster virus 
• herpes simplex virus – a type of virus that often causes cold sores

Causes of acquired cataracts

Cataracts that develop in children at some point after they are born are known as acquired, infantile or juvenile cataracts.

Causes of this type of cataracts can include:

• galactosaemia – where the sugar galactose (which mainly comes from lactose, the sugar in milk), cannot be broken down by the body 
• diabetes – a lifelong condition that causes a person’s blood sugar level to become too high
• eye trauma – as a result of an injury to the eye or eye surgery
• toxocariasis – a rare parasitic infection that can sometimes infect the eyes, spread from animals to humans via their infected faeces

However, most of these problems are either rare or don’t normally cause cataracts to develop in children.

Although cataract surgery is very successful, some children may experience complications and need further treatment.

Even if a child’s cataracts are successfully removed during surgery, their vision may still be affected by other eye conditions.

For example, lazy eye can occur if there is weaker vision in one eye. This causes the brain to ignore the visual signals coming from the weaker eye, resulting in vision in the affected eye not developing properly. Lazy eye will need further treatment, usually by wearing a patch over the stronger eye, although it may not always be possible to fully correct the problem.

Cloudy vision

If your child has an artificial lens fitted during cataract surgery, the main risk is a condition called posterior capsule opacification (PCO). This is where part of the lens capsule (the ‘pocket’ that the lens sits inside) thickens and causes cloudy vision. This is not the cataract returning, but is caused by cells growing over the artificial lens.

PCO is common after cataract surgery where an artificial lens is implanted and it usually develops within four to 12 months of having the operation.

If your child develops PCO, they may need another operation to correct it. This will be done with laser eye surgery (when energy beams are used to cut through part of the eye). During laser eye surgery, the cloudy part of the lens capsule will be removed, with enough left to continue holding the artificial lens in place.

This procedure should only take around 15 minutes, and vision should be improved immediately or within a few days. As no surgical incisions or stitches are necessary, your child can usually return to their normal activities straight away. 

Other complications

Other complications that can occur after an operation to remove childhood cataracts include:

• glaucoma – where vision is affected by increased pressure inside the eye
• squint – where the eyes look in different directions
• abnormalities affecting the pupil, such as it becoming a more oval shape – this is common and doesn’t usually affect vision
• retinal detachment – where vision is affected by the retina (layer of nerve cells inside the back of the eye) becoming separated from the inner wall of the eye
• cystoid macular oedema – where fluid builds up between layers of the retina, sometimes affecting vision
• infection – such as endophthalmitis (a rare bacterial infection)

In many cases, medication or further surgery will be required to treat these problems if they develop.

When to seek medical advice

If your child has any signs of pain, bleeding, a lot of stickiness or redness in or around the eye after surgery, contact the hospital where the operation was carried out immediately.

It is important childhood cataracts are diagnosed as early as possible because early treatment can significantly reduce the risk of long term vision problems.

Newborn screening

As part of the UK Healthy Child Programme, your baby’s eyes will be routinely examined within 72 hours of birth and again when they are six to eight weeks old.

Childhood cataracts are among the conditions screened for during these examinations.

During screening your baby’s eyes are checked by looking at their general appearance and how they move. If your baby’s eye looks cloudy, it could be a sign they have cataracts.

Vision tests for older babies and children

Although cataracts can be present from birth, they sometimes don’t develop until a child is older. Visit your GP or tell your health visitor if you have any concerns about your child’s eyesight at any stage.

You should also make sure your child has routine eye tests to look for any problems with their vision. All children under the age of 16 are entitled to free sight tests, which they should have about every two years.

Read more about vision tests for children and NHS eye care services.

Referral to a specialist

If it is thought your baby or child may have cataracts, they will usually be referred to hospital to see an ophthalmologist as soon as possible. An ophthalmologist is a doctor who specialises in eye conditions and their treatment.

Before the ophthalmologist examines your baby, they will apply drops to their eyes to dilate (widen) their pupils. The drops will not hurt your baby, and the effect will wear off after a few hours.

The ophthalmologist will then examine your baby’s eyes using an ophthalmoscope (a medical instrument that has a light on the end and produces a magnified image of the eye). This shines a bright light into your child’s eyes and enables the ophthalmologist to look inside them.

The ophthalmologist may diagnose cataracts if they can see the cataracts in the lens or if the examination shows a poor ‘red reflex’ in the pupil. The red reflex is like a reflection from the back of the eye similar to the red eye effect sometimes seen in flash photography. If the examination shows no red reflex, or a weak one, it may mean there is cloudiness in the lens.

If your child is diagnosed with cataracts, the ophthalmologist will discuss the treatment options with you. Read more about treating childhood cataracts.

Cataracts are cloudy patches in the lens of the eye that can make vision blurred or misty.

The lens is the transparent structure positioned just behind the pupil (the black dot in the centre of the eye). It allows light to pass through to the back of the eye (retina).

Cataracts most commonly develop in adults as a result of aging (age-related cataracts), but some babies are born with cataracts and children can also develop them at a young age. These are known as childhood cataracts.

Childhood cataracts are often referred to as:

• congenital cataracts – cataracts that are present when a baby is born or shortly afterwards
• developmental, infantile or juvenile cataracts – cataracts that are diagnosed in older babies or children

Cataracts in babies and children are rare. It’s estimated that they affect between three and four in every 10,000 children in the UK.

Symptoms of cataracts in children

In children, cataracts can affect one or both eyes. The patches can sometimes get bigger and more can develop, meaning that vision may become increasingly affected.

When your child is very young, it can be difficult to spot signs of cataracts. However, your baby’s eyes will be routinely examined within 72 hours of birth and again when they are six to eight weeks old.

Sometimes cataracts can develop in children after these screening tests, causing symptoms such as poor vision, ‘wobbling’ eyes and a squint (where the eyes point in different directions).

It is particularly important to spot cataracts in children quickly because early treatment can reduce the risk of long-term vision problems. Therefore, you should visit your GP or tell your health visitor if you have any concerns about your child’s eyesight.

Read more about the symptoms of childhood cataracts and diagnosing childhood cataracts.

What causes cataracts in children?

There are a number of reasons why a child may be born with cataracts or develop them while they are still young, although it is not possible to determine the exact cause in many cases.

Possible causes include:

• a genetic fault inherited from the child’s parents that caused the lens to develop abnormally
• certain genetic conditions – including Down’s syndrome
• certain infections picked up by the mother during pregnancy – including rubella and chickenpox
• an injury to the eye after birth

Read more about the causes of childhood cataracts.

How childhood cataracts are treated

Cataracts can be mild in children and sometimes have little or no effect on their vision.

However, if cataracts are affecting your child’s vision, they can slow down or stop their normal development of sight.

In these cases, surgery to remove the affected lens (or lenses) will usually be recommended as soon as possible.

The affected lens may sometimes be replaced with an artificial lens during surgery, although it is more common for the child to wear contact lenses or glasses after surgery to compensate for the lens that was removed.

It can be difficult to predict exactly how much better your child’s vision will be after treatment, although it is likely there will always be a degree of reduced vision in the affected eye (or eyes). However, most children with childhood cataracts are able to go on to live a full and normal life.

Read more about treating childhood cataracts.

What are the risks?

Cataracts affecting vision that are not quickly treated can sometimes cause irreversible damage to eyesight, including a permanently lazy eye and even blindness in severe cases.

Cataract surgery is generally very successful, with a low risk of serious complications. The most common risk associated with cataract surgery is a condition that can affect artificial lens implants called posterior capsule opacification (PCO), which causes cloudy vision to return.

Although some of the possible complications of cataract surgery can affect your child’s vision, they can often be treated with medication or further surgery.

Read more about the complications of childhood cataracts.

Can cataracts in children be prevented?

It’s not usually possible to prevent cataracts, particularly those that are inherited (run in the family).

However, following the advice of your midwife or GP to avoid infections during pregnancy (including making sure all your vaccinations are up to date before getting pregnant) may reduce the chances of your child being born with cataracts.

If you have previously had a baby with childhood cataracts and are planning another pregnancy, you may wish to speak with your GP about whether genetic counselling would be appropriate. Genetic counselling can help couples who may be at risk of passing an inherited condition onto their child.

Read more about infections in pregnancy and genetic testing and counselling.

Symptoms of childhood cataracts can vary depending on how cloudy the lens is, where the cloudiness is in the lens, and whether one or both eyes are affected.

When your child is very young, it can be difficult to spot signs of cataracts. However, your baby’s eyes will be routinely examined within 72 hours of birth and again when they are six to eight weeks old as part of the Healthy Child Programme.

Sometimes cataracts can develop in children after these screening tests. Signs that your child may have developed cataracts can include:

• poor vision – you may notice your child has difficulty recognising and following objects or people with their eyes
• rapid uncontrolled eye movements or ‘wobbling’ eyes – known as nystagmus
• the eyes pointing in different directions – known as a squint
• a white or grey pupil – this can also be a sign of other serious conditions and should be immediately checked by a doctor

Your child may also find it particularly difficult to see clearly in bright light or if there is any glare.

When to seek medical advice

Visit your GP or tell your health visitor if you have any concerns about your child’s eyesight at any stage.

Your GP can examine your child’s eyes and can refer them to an eye specialist for further tests and treatment if necessary.

Read about diagnosing childhood cataracts.

Whether or not your child needs cataract surgery will largely depend on whether their vision is affected.

If cataracts are not causing any problems, immediate treatment may not be necessary.

Instead, your child may only need regular check-ups to monitor their vision.

If your child’s vision is affected by cataracts, they will usually need to have surgery to remove the cloudy lens (or lenses) followed by the long-term use of glasses or contact lenses.

As childhood cataracts are rare, it is difficult to predict how much a child’s vision will be improved by treatment. Many children are likely to have reduced vision in the affected eye (or eyes) even with treatment, although most will be able to go to mainstream schools and go on to live full lives.

Cataract surgery

Cataract surgery for babies and children will take place in hospital under general anaesthetic, meaning that during the operation your child is asleep.

The operation, which usually takes between one and two hours, will be performed by an ophthalmologist (a doctor specialising in the treatment of eye conditions).

If the cataracts are present from birth, the operation will be carried out as soon as possible, usually a few weeks after your baby is born.

Before the operation, the ophthalmologist will apply drops to the eye to dilate (widen) the pupil. A very small cut is made in the surface (cornea) at the front of the eye, and the cloudy lens is removed.

In some cases, a clear plastic lens called an intraocular lens (IOL) or intraocular implant will be inserted during the operation to replace the lens that was removed. This is because the eye cannot focus with a lens.

However, it is more common in babies and young children for external contact lenses or glasses (if both eyes are affected) to be used to compensate for the removal of the lens. These will be fitted a week or two after the operation. 

Most ophthalmologists recommend using contact lenses or glasses because there is a higher risk of complications and further surgery being needed in babies and young children who have an IOL inserted.

When the operation is complete, the incision in your child’s eye will usually be closed with stitches that gradually dissolve.

After the operation

After the operation, a pad or transparent shield will be placed over your child’s eye to protect it. Most children will need to stay in hospital overnight so their recovery can be monitored.

If your child has cataracts in both eyes (bilateral cataracts), the ophthalmologist will normally operate on each eye separately to reduce the risk of complications affecting both eyes. You and your child will be able to go home between operations. The second operation will usually take place within a week of the first.

You will be given eye drops to give to your child at home. These help reduce inflammation (swelling and redness) in the eye. You will need to put them into your child’s eye every two to four hours – you’ll be shown how to do this before you leave hospital.

Read about the risks of childhood cataract surgery for information about the problems that could develop after your child’s operation.

Further treatment

Most children will need to wear glasses or contact lenses after cataract surgery. This is because vision in the treated eye or eyes will be blurred, as they are no longer able to focus properly on their own.

Glasses or contact lenses will also usually be needed if an artificial lens has been fitted, to allow your child to focus on closer objects. This is because artificial lenses can usually only focus on more distant objects.

The glasses or contact lenses will usually be fitted a few weeks after the operation, usually by an eye specialist called an orthoptist. The orthoptist will advise you about how often any contact lenses should be replaced (usually every day) and they will teach you how to do this.

Your child will continue to have regular check-ups with an orthoptist after surgery so their vision can be monitored. As your child’s vision develops with age, the orthoptist can adjust the strength of your child’s contact lenses or glasses.

Wearing a patch

If you child has weaker vision in one eye, the orthoptist may also recommend that your child wears a temporary patch over their stronger eye. This is known as occlusion therapy.

This treatment aims to improve vision in the weaker eye by forcing the brain to recognise the visual signals from that eye that it may have been ignoring previously.

Your orthoptist will tell you when your child should wear the patch and how long they may need it for. This will depend on the type of cataract your child had, and how weak their vision is. Wearing a patch can be an unpleasant experience for your child, and they will need lots of encouragement to keep it on.