Eyes - Congenital cataracts

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A cataract is cloudiness in the lens of the eye. This means the lens is no longer transparent. The lens is located behind the iris (the coloured part of the eye), and focuses light rays on to the retina. The retina is the inner layer at the back of the eye. For a child to be able to see, light has to pass through the transparent lens to the retina.

In a normal eye the cornea and the lens focus light rays onto the retina
Lens with a cataract, blocking the light rays so the eyesight is reduced

Cataracts can occur in one or both eyes. What causes most cataracts is unknown. We do know that some cataracts are linked to metabolic and infectious diseases (like rubella) and some syndromes. In most cases, the cause cannot be identified. About one third of cataracts are hereditary. For example, the child's grandparent or parent may have been born with a cataract. The parent and child usually have a cataract in the same part of the lens, as well as the same type of cataract.

Most cataracts are invisible until they became dense enough to cause loss of sight. When the lens becomes cloudy it thickens and the pupil appears white. Congenital cataracts can vary in density. If the cataract is not dense enough to interfere with vision (), it may require no treatment. The ophthalmologist will continue to monitor your child. Once the cataract reduces your child's vision, the lens will be removed. Dense central cataracts require surgery - if they go untreated, vision will not be able to develop in that eye.

Some of the symptoms of cataracts

  • Glare - the same effect as car headlights through a dirty windscreen at night.
  • A white pupil known as leukocoria - this is due to the cataract showing through the pupil. The pupil is just a hole or opening which allows  light to enter the eye
  • Poor vision - light is not getting through the lens, because it's no longer transparent.
  • In an older child the eye can turn. This is called strabismus, or squint. A “turn” occurs because the eye can not focus properly.

To diagnose the congenital cataract, the ophthalmologist will examine your child's eyes with an instrument called an ophthalmoscope. Before the examination, the pupils of the eyes have to be dilated with eye drops in order to view the lens and retina properly.

If your child needs surgery

Cataracts are usually treated by surgically removing the lens of the eye. The lens is removed by making a small incision in the eye. The operation usually takes about an hour. Your child may either stay for the day or may have to stay in hospital overnight. Your child will return to the ward with an eye pad covering the operated eye. This pad will be removed the next day. Not all cataracts need surgery.

After the operation

After the operation, your child will need eye drops frequently during the day for a period of time. Because the lens is used to focus the light rays, the child won't be able to focus on objects. The doctor will prescribe a contact lens or glasses. An intra-ocular lens (a lens implanted in the eye) can also be used in place of the eye lens, in some children

Contact lenses are usually the preferred choice for unilateral (one side) cataracts- these lenses can stay in the eye for a week at a time. Parents are taught how to put in and clean the contact lens. We make sure that you feel confident in handling the day- to-day care of your child's lenses.

Patching of an eye may be needed to avoid vision problems.


  • Cataracts are usually treated by surgically removing the lens of the eye.
  • Your doctor will prescribe contact lenses or glasses.
The Children's Hospital at Westmead
Sydney Children's Hospital, Randwick
Hunter New England Kids Health

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