When a child has congenital cataract in just one eye, the brain tends to rely on the eye without a cataract, It learns to ignore or “switch off” from the eye with the cataract and reduced vision. This makes it difficult for the visual pathway in the affected eye to develop properly.
Congenital cataracts
A cataract can make your vision blurry or misty, a bit like trying to look through frosted glass. Some babies are born with cataracts or develop cataracts at a very early age. This is known as congenital or infantile cataracts.
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- A cataract is a clouding of the lens inside your eye.
- It can make your vision blurry or misty – a bit like trying to look through frosted glass.
- Some babies are born with cataracts or develop cataracts at a very early age.
- If a cataract develops in the first six months of life, it is known as an “infantile cataract”.
- Children can have cataract in one (unilateral) or both (bilateral) eyes.
- Some cataracts do not affect vision and do not need any treatment.
- Most children with cataract in only one eye usually have good vision in the other eye.
- If one eye doesn’t get clear images because of a congenital or infantile cataract, the brain may start to ignore it. This means the vision in this eye won’t develop properly – this is called amblyopia or “lazy eye”.
- If the cataract is affecting your child's vision, surgery will usually be considered to remove the affected lens from the eye.
- Treatment will usually also involve glasses or contact lenses and patching to help vision develop as fully as possible.
How does our vision develop in childhood?
When a baby is born, their eyes and brain need to learn how to work together. As a child grows, the eyes collect visual information and send it to the brain to process. Over time, this builds strong connections between the eyes and the brain. This connection is known as the visual pathway.
The visual pathway develops throughout childhood, until seven or eight years old. During this time, it’s important that both eyes send clear and similar images to your brain. The brain uses this visual information to improve how the eyes work together (their co-ordination), helping the visual pathway to develop fully. The most crucial time is the first two to four months of life. If the brain doesn’t receive clear images during this time, it may never learn to see clearly.
After the age of about eight years old, the visual pathways and the “seeing” parts of the brain are fully developed and are difficult to change. If a child is born with an eye condition which affects vision, such as cataract, then their visual pathway may not develop fully. This is because a cataract reduces the visual signals reaching the brain. That’s why it’s critical to treat vision problems which happen in the first few months of life as early as possible.
How can congenital or infantile cataract affect vision?
If your child has cataract in one eye, that eye will send blurry and unclear images to the brain. Over time, the brain will learn to ignore these images in favour of those coming from the better seeing, or “stronger” eye. This stops the visual pathway in the eye which has the cataract, from developing properly. This is known as amblyopia or “lazy eye”. If it’s not treated, amblyopia can cause permanent reduced vision in the weaker eye because the brain has never learnt to process clear images from it. This is especially important if it happens in the first few months of life, when visual development is most critical.
There are many types of congenital cataract. Some affect vision and others never do. Cataracts in the centre of the lens are more likely to affect vision and visual pathway development, than those around the edges of the lens. However, the impact will depend on the cataract’s size and how dense, or cloudy it is.
Very dense cataracts can lead to blindness in babies if left untreated, or if treated too late.
Congenital cataracts can continue to develop, but this normally takes months to years.
An ophthalmologist (hospital eye doctor) will check your child’s eyes and vision and tell you how much the cataract is affecting their vision. They will then discuss treatment with you if they feel it is needed.
If a child has cataracts in both eyes, each eye sends a blurry image to the brain. As a result, the brain will ignore the images from both eyes. The visual pathway may still develop, but it would be limited, leading to some vision being reduced permanently.
What causes congenital cataracts?
Around 3 in 10,000 children in the UK are born with a cataract which affects vision. In around a third of cataracts the cause is unknown, and the cataract isn’t linked to any other disease or condition.
Cataracts in just one eye usually have no known cause. Sometimes, they may be linked to:
- other conditions in the eye, such as having an unusually small eye
- eye structures that didn’t develop properly while the baby was in the womb.
Cataracts in both eyes are more likely to run in families, which means a baby might inherit them. They can also be linked to:
- other conditions affecting the entire body,
- infections during pregnancy, such as measles or rubella
- metabolic conditions, which affects how the body turns food into energy.
If a cataract is passed down from a parent, one parent may know that they have cataracts themselves but sometimes they may only have a tiny cataract which doesn’t affect their vision and which they’re unaware of. This is why it can be helpful for the ophthalmologist to examine the eyes of the parents and siblings of a child with cataract even if they’re unaware of any issues with their eyes.
Most children who are born with or develop infantile cataracts do not have other medical problems, however some do. If an ophthalmologist (eye doctor) is concerned that a baby may have other health conditions they will arrange for an examination from a paediatrician (a doctor specialising in children’s conditions).
How are congenital cataracts diagnosed?
If a doctor suspects that your child has a cataract at birth, they will refer them to an ophthalmologist for a full eye examination. An ophthalmologist would carry out this examination at hospital.
In the UK, all babies are screened for eye problems, including congenital cataracts, within the first 72 hours after birth. Babies are then usually checked again by a health visitor or community doctor around six to eight weeks old.
If you are worried about your baby's vision, speak to your health visitor. Your baby’s “red book” (Personal Child Health Record) includes information on how their vision should develop. If your health visitor notices any signs of a possible eye problem such as cataract, they will refer your baby to a hospital ophthalmologist for a full examination.
If cataracts develop later in childhood and affect vision, there may be noticeable signs. For example, sometimes a child may:
- have difficulty focusing on certain objects
- develop a wobbly movement in the eyes (nystagmus)
- hold their head at an unusual angle
- develop a squint (a turn in one eye).
If you’re concerned at any stage that your baby or child isn’t seeing normally, speak to your GP or an optometrist (optician). They can check your child's eyes and refer them to see an ophthalmologist.
A cataract would not change the appearance of the eye, so parents are unlikely to see a cataract just by looking at their baby’s eyes. In rare cases, if the cataract is very dense, the pupil may look white because the cloudy lens is visible through it. However, a “white pupil” can also be caused by other serious eye conditions, so it should always be checked urgently by a doctor.
What is the treatment?
Some cataracts do not affect vision and do not need any treatment. If the cataract is affecting your child's vision, surgery will be considered to remove the affected lens from the eye. Treatment will usually also involve glasses or contact lenses and patching to help vision develop as fully as possible.
Once a cataract is removed it cannot grow back.
If your baby’s cataract is likely to significantly affect vision, surgery is considered early, often before the age of three months. This is because visual development in the first few months of life is critical. Sometimes, very young children may be referred to a nearby specialist centre to have their cataract surgery.
The ophthalmologist will discuss the options with you, explaining the risks and benefits of surgery so that you can make an informed decision.
Bilateral cataracts (both eyes)
- Small cataracts affecting only a small part of the lens may just need monitoring.
- Dense cataracts that are likely to interfere with vision are usually removed, very early, during the first few months of life.
- If one eye has a denser cataract than the other, the eye with the denser cataract is usually treated first. Surgery on both eyes may be done on the same day or scheduled very soon after the first one.
Unilateral cataracts (one eye)
- A large cataract in the centre of the lens generally needs surgery early for the best chance of good vision.
- A small cataract, or one that doesn’t affect the centre of the lens, may not need surgery straight away. Instead, occlusion treatment may be prescribed. This involves patching or using drops in the good eye so that the weaker eye is encouraged to see and develop. Even small cataracts can cause amblyopia, so treatment may still be recommended. More details about patching are explained under “occlusion therapy” later in this information.
Your child will be given a general anaesthetic so that they will not feel anything during the operation.
The surgeon will make small openings in the side of the cornea at the front of the eye. Through these, they will then make a small opening in the natural bag which holds the natural lens. The cloudy lens is then removed through these openings using suction.
In younger children, the tiny openings made in the cornea are closed with stitches that dissolve on their own. This may not always be needed in older children.
Before going home, the clinical team will monitor your child’s recovery from the surgery and explain how to care for your child’s eye. Young babies may need to stay in hospital overnight, but older children will usually be able to go home the same day.
Once your child's cloudy natural lens has been removed, it may be replaced with a clear artificial lens implant, called an intraocular lens or IOL. If an IOL is used, it is usually intended to last for life and not need replacing.
For very young children (under two years old), the ophthalmologist may recommend using a contact lens on the front of the eye instead of an IOL.
An IOL is often used in older children, but the decision is very individual. The ophthalmologist will discuss the risks and benefits of using an IOL for your child. They would consider your child's level of vision and their age.
Most children will have an IOL implanted at some point but will usually still need glasses or contact lenses to achieve the best possible vision.
The clinical team will show you how to put drops into your child's eye before they are discharged from the hospital. Putting drops and/or ointments into a baby’s eye can be tricky. There are some very helpful videos that you can watch online showing different techniques that can be used to instil drops in young babies and children:
- How to put eyedrops in children and babies
- How to give medicines: eye drops and eye ointment - Medicines For Children
The clinical team will explain post-operative care including:
- How to bath your child safely. It’s important to protect and keep the eye clean after surgery. Avoid getting water or shampoo in the eye. This is to give their eye the best recovery and to minimise the risk of infection.
- How to use a plastic eye shield. The hospital may provide an eye shield, which is especially useful at night. The shield protects the eye and helps prevent your child from rubbing it while it heals. The clinical team will tell you when and how long to use the shield.
- How to keep the eye clean without wiping inside it or washing it out.
You will usually receive a written instruction sheet explaining how to care for your child’s eye during recovery.
If you notice any swelling, bleeding, a lot of stickiness, redness in or around your baby's eye, or if they seem to be in pain after surgery, contact the hospital immediately, or go to the eye emergency department, so your child can be seen quickly. Your surgeon should let you know where to go if problems develop.
Complications can often be treated successfully if they are caught early enough. If you have any concerns about your child’s eye or post-operative care, contact the hospital where the surgery took place. Parents and carers will often be given 24-hour contact details before leaving the hospital.
After cataract surgery, most children will need glasses or contact lenses. This is because the IOL or contact lens used to replace your child's natural lens has a fixed focus. Unlike the natural lens, it can't change shape to focus on objects both near and far. Glasses or contact lenses will help make sure your child can see as clearly as possible at all distances. Clear vision is essential for your child’s visual development, so it’s important that glasses and contact lenses are worn as prescribed. and make sure that a clear image is being presented to their developing brain. Your child might need:
- glasses or contact lenses for both near and distance vision, or
- bifocal glasses, where the top part corrects distance vision and the bottom part corrects near vision.
If your child does not have an IOL implanted during cataract surgery, they will need glasses and/or contact lenses with a strong prescription. This will make the glasses thick and heavy. Sometimes in very young babies, it can be difficult to find glasses that will stay on a baby’s face. For these reasons, contact lenses are often a more practical solution.
Glasses or contact lenses will often be prescribed a few weeks after the operation, usually by an optometrist (optician). They'll advise you about how often contact lenses should be replaced (usually every day) and teach you how to do this.
If your child is under the age of one, the hospital may check their eyes every two to three months to monitor how well they are focusing. As your child grows, their eyes also grow, so it is common for glasses and contact lens prescriptions to change frequently in the first few years.
Patching the eye with better vision encourages your child to use their weaker eye and aims to encourage the vision in the weaker eye to develop. This is known as occlusion therapy.
For unilateral cataracts or bilateral cataracts with one eye worse than the other, patching the better eye is often just as important as the surgery itself. Without patching, children with cataracts affecting one eye are very unlikely to develop good vision, even after surgery.
Amblyopia (lazy eye) can develop when the brain ignores or switches off from the eye with worse vision and just uses the eye with the better vision. Patching the eye with better vision encourages your child to use their weaker eye. It’s an important treatment to help develop your child’s vision and prevent amblyopia. But it can be a lengthy process and very demanding for both the child and parent.
It is usually managed by an orthoptist at the eye clinic. Orthoptists are experts in how the two eyes work together (known as binocular vision).
- Your child's better seeing eye may be patched for several hours a day in early childhood
- It is important to follow prescribed timings for patching. Some parents may feel that extra time patching may benefit but this may cause problems with normal vision development in the better eye
- Strictly following the orthoptist’s patching advice gives your child the best chance of developing the best vision possible in the weaker eye
- If cataracts have been removed in both eyes and one eye sees better than the other, patching the better seeing eye for short periods may be recommended
- The orthoptist may advise you patch your child’s better eye even if they have not had cataract surgery, to help the vision in the eye with the cataract to develop.
- There are different types of “patches” that can be used; some can be stuck onto the face and others can be put over glasses or worn “pirate style”. The orthoptist can explore which ones would work best for your child
- Techniques to encourage your child to wear their patch could include reward charts/stickers, associating patching with enjoyable activities such as games, music, etc.
- Continue to be persistent and consistent with patching. Asking teachers, family members and friends to help and encourage your child may also help them understand that it is something that must be done
- If wearing a patch is not possible then sometimes drops can be put in the stronger eye to blur vision for a period of time, rather than wearing a patch.
How about the future?
With early detection, treatment, and dedication of parents and carers, many children with congenital cataracts in the UK go on to have a good level of vision. The effort and perseverance by parents and carers in supporting their child’s treatment leads to the best possible visual outcomes.
Children with unilateral cataract can have reduced vision in that eye, but if vision in the other eye is normal, then overall vision is usually very good. Children adapt well to using their better eye. This does not cause damage or overuse of the better eye. It’s unusual for children with good vision in one eye to need additional support in school. If the vision in the good eye meets driving standards, they can drive a car in future.
Children with bilateral cataracts may have reduced vision in both eyes. Vision tends to be better if there are no other eye conditions or complications after surgery. Most will attend mainstream school but may require additional support.
Ongoing care
Regular checks with the eye clinic or an optometrist are important to ensure your child is wearing the correct glasses or contact lenses, so their vision can develop as fully as possible. The eye clinic or optometrist will advise you on how often these checks are needed.
Some children with cataract may also have other eye or health problems. These are usually detected early by heath care professionals, with treatment or support given where needed. Speak to your eye team or GP if you have any other concerns.
Page last reviewed: Sept. 1, 2022
Next review due: Jan. 31, 2023
