Cataracts, childhood

Cataracts are cloudy patches or areas in the lens inside your eye. The lens in the eye is normally clear. If parts of the lens are cloudy (opaque), light cannot pass through them.

Cataracts can affect babies and older children, as well as adults. For example, cataracts can be:

  • Present when a baby is born or shortly afterwards. These are called congenital cataracts.
  • Diagnosed in older babies or children. These are sometimes called developmental, infantile or juvenile cataracts.

Childhood cataracts can develop in:

  • One eye (unilateral).
  • Both eyes (bilateral).

In babies and children, cataracts can be mild and have little or no effect on their vision. However, they can also slow down or stop the normal development of sight during childhood.

Severe childhood cataracts that are not treated can cause irreversible damage to the eyesight, including blindness. However, childhood cataracts are very rare, affecting about three in 10,000 babies. In around two-thirds of cases, both eyes are affected. 

Common causes of childhood cataracts can include genetic conditions and infections during pregnancy. However, in many cases, it is not possible to determine the cause.

Genetic causes

Cataracts present from birth can be inherited (run in the family). Cataracts can also be associated with conditions caused by chromosome abnormalities, such as Down's syndrome.

Other causes

Cataracts present from birth can be caused by infections during pregnancy. The most common can include:

  • rubella (German measles),
  • toxoplasmosis,
  • cytomegalovirus, and
  • chickenpox.

Cataracts present from birth can also be linked to other eye conditions, such as:

  • retinopathy of prematurity (a condition found mainly in babies born before 37 weeks of pregnancy), or
  • aniridia (a rare condition where the iris is not formed properly).

Conditions that affect the metabolism can cause cataracts, sometimes in older babies or children. For example:

  • galactosaemia, or
  • diabetes.

These conditions are rare in babies and children.

Injuries to the eye can also cause cataracts.

It is important to diagnose congenital cataracts as early as possible, ideally during the first few weeks after a baby is born, to help reduce sight loss.

Screening of newborn babies

In the RSA, parents of newborn babies are offered two full physical examinations for their babies:

  • the first within 72 hours of the baby's birth, and
  • the second when the baby is about 6-8 weeks old.

Congenital cataracts are one of the conditions screened for in these examinations.

The health professional will look at your baby's eyes, to check on their general appearance and how they move. If their eye looks cloudy, it could be a sign of cataracts.

Sometimes, it can be difficult to check the eyes of newborn or very young babies. For example, if:

  • their eyelids are swollen,
  • their eyes are closed, or
  • they are unsettled, anxious or irritated.

Even though cataracts may be present from birth, sometimes they are not diagnosed until the baby or child is older.

For more information about newborn babies' physical examinations, see the 'related articles' section.

Checking children's eyes

If your baby or child may have cataracts, your GP or other healthcare professional will refer them to a doctor who specialises in:

  • treating eyes (ophthalmologist), or
  • children's eyes (paediatric ophthalmologist).

Other healthcare professionals may also be involved in their care, such as a doctor who specialises in children's treatment (paediatrician).

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

Then the doctor will examine your baby's eyes by looking at them with an ophthalmoscope. This instrument shines a bright light into the eye and enables the doctor to see inside it.

The doctor may diagnose cataracts if:

  • they can see them in the lens, or
  • 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 if it is less strong than usual, this may mean that there is cloudiness in the lens.

Other tests

If there is no family history of childhood cataracts, your doctor may also carry out some other tests to try to identify the cause and diagnose the condition. For example:

  • blood tests, and
  • urine samples.

The symptoms of childhood cataracts can vary. For example, the symptoms can depend on:

  • how cloudy (dense) the lens is,
  • where the cloudiness is in the lens, and
  • whether one or both eyes are affected.

A cloudy lens

Pupils are the black circles in the middle of each of your eyes. The lens is behind the pupil.

If a baby has cataracts, the pupil in their eye may look white or cloudy. Sometimes it may be possible to see this cloudiness in the eye without using special equipment, such as an ophthalmoscope.

Mild cataracts may not affect the vision, or affect it only slightly. The cloudier the lens is, the more the child's sight will be affected.

Severe cataracts can make a child's vision blurry or cloudy. If a baby has severe cataracts in both eyes, they may not seem to see or be aware of what is going on around them.

The position of cataracts can also affect vision. For example, cataracts towards the centre of the lens may affect the vision more than cataracts towards the side of the lens.

Identifying symptoms

Sometimes it can be difficult to identify symptoms of cataracts in babies and children.

Even an older child may not realise anything is wrong with how they see, as they do not know any different. For example:

  • If they have cataracts in one eye, they may not notice that the affected eye's vision is poorer, because they rely on the vision in their other eye.
  • If they have cataracts in both eyes, one eye may be affected more severely than the other. This can mean that the brain learns to rely on the stronger eye, because the weaker eye stops working as hard and its vision becomes poorer.

Other eye conditions

Children who have cataracts sometimes have other eye conditions as well. For example:

  • microphthalmia (abnormally small eyes), and
  • nystagmus (rapid uncontrolled movements of the eye).

If your baby or child has cataracts, whether or when treatment is needed may depend on, for example:

  • if one or both eyes are affected, and
  • how mild or severe the cataracts are.

Because childhood cataracts are so rare, it may be difficult for doctors to predict how much their vision may be improved.

How are childhood cataracts treated?

Cataracts in babies and children may be treated by:

  • removing the cloudy lens in an operation and replacing it with an artificial lens,
  • wearing glasses,
  • wearing contact lenses, or
  • a combination of these treatments.

Cataract operations for babies and children take place in hospital under general anaesthetic. Before the operation, the doctor will apply drops to the eye to widen (dilate) the pupil.

Removing the natural lens means that the eye cannot focus.

During the operation, the natural lens may be replaced with a clear plastic lens. This is called an intraocular lens (IOL) or intraocular implant.

Sometimes, a contact lens on the eye's surface may be used instead, to help the eye to focus.

Cataracts in one eye

If your baby or child has cataracts in one eye (unilateral), they may need to have an operation.

If the condition is present from birth, your baby will probably have the operation a few weeks after they are born.

Cataracts in both eyes

If your baby or child has cataracts in both eyes (bilateral), the doctor will probably operate on each eye separately.

If the cataracts are present from birth, the operations will be done as soon as possible.

You will both be able to go home after the first operation. The doctor will probably do the second operation about a week later.

After the operation

After the operation, the doctor or nurse will put a pad over the eye to protect it.

You will be given eye drops to give your baby or child at home.

The drops help to reduce inflammation. You will need to put them into the eye every 2-4 hours. The nurse will show you how to do this before you leave hospital.

Future treatment

After a cataract operation, your baby or child will have regular check-ups.

They will probably have their vision tested regularly by a specialist in eye problems (orthoptist). This will help to pick up and correct any changes in their vision as early as possible.

Most children will need to wear:

  • glasses or contact lenses to improve their vision – these will probably be fitted a few weeks after the operation, and
  • a patch over their eye – this is called occlusion therapy.

Contact lenses can be used to treat babies as well as older children.

Patch over the eye

In occlusion therapy, the stronger eye is covered with a patch, so that the child uses only the weaker one to see.

This treatment aims to improve vision in the weaker eye. It makes the brain recognise the visual signals from that eye and improves the images it sees.

The doctor will tell you when your child should wear the patch and how long they may need it for.