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What is a cataract?

A cataract is a cloudy area over the lens of the eye. Cataracts can affect one or both eyes. Childhood cataracts are rare: they occur in one to three in 10,000 children.

A healthy eye

The eye is like a camera. It records pictures of what it sees. But to see clearly, all parts of the eye must work properly.

  • The cornea is a clear outer covering at the front of the eye. It covers the iris and pupil.
  • The sclera, or white part of the eye, is the continuation of the cornea around into the back the eye.
  • The iris is the coloured part of the eye and controls how much light enters through the pupil.
  • The pupil is the window in the centre of the iris.
  • The lens is behind the pupil. It is designed to focus the rays of light onto the retina, just like a camera lens focuses an image onto a film.
  • The retina is the innermost covering of the eye. It converts the rays of light into an electrical signal and sends the signal to the brain.
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What happens when your child has cataract(s)

When your child has a cataract, the lens cannot focus the rays of light onto the retina normally. Instead, the lens produces blurry images, which reduce the child's vision.

Your child's vision might be mildly or seriously affected by a cataract, depending on how big it is and where it covers the lens. A cataract will not affect your child's vision if it is very small or away from the centre of the lens. 

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A normal clear lens focuses the image on the retina. A lens clouded by a cataract results in a blurry image.

Causes of cataract

A cataract can be congenital (a person is born with it) or can be acquired or developmental (it appears later in childhood or in adulthood).

Common causes include:

  • heredity (inheriting a cataract from a parent)
  • trauma (injury) to the eye
  • radiation (treatment for cancer)
  • medication (for example steroids)
  • other illnesses or conditions (for example Down syndrome)
  • infection (for example German measles).

In many cases, however, the cause of a cataract is not known.

How to tell if your child has a cataract

Have your child's eyes examined by an ophthalmologist (say: op-thal-MOL-o-jist), a medical eye doctor, if:

  • you notice a white spot on your child's eye(s)
  • a parent or sibling had a cataract as a child (not as an older adult)
  • your child has eye problems or another disease or condition in which cataracts are likely to be present
  • your family doctor or paediatrician recommends an eye exam because of a concern about possible cataracts
  • your child's eyes are crossed
  • there is a concern about your child's vision.

If there is a family history of cataracts in childhood, bring your child to an ophthalmologist before he is two weeks old.

Checking your child's eyes for cataracts

The ophthalmologist will carefully examine your child's eyes. Here is what you can expect during the exam.

  • Your child will have special eye drops to make his pupils bigger. These drops sting at first but only for about 10 seconds. They may be repeated.
  • Since your child needs to be very still when the eyes are checked, he may be wrapped in a blanket and held down gently, especially if he is very young or too upset to stay still on his own.
  • When the drops start to work, usually after about 30 minutes, the ophthalmologist will shine a bright light into your child's eyes and use different instruments to help check them.

Being held down and having a bright light shone in his eyes will make your child uncomfortable, but he should not feel any pain.

After the exam, the eye doctor will explain the condition of your child's eyes. If there is a cataract, the doctor will tell you and talk to you about the best treatment for your child.

Treatments for cataracts

Cataracts do not go away by themselves, except in a few rare situations.

Mild cataract

If the cataract is small and does not affect your child's vision, the doctor may decide not to treat it at all or may prescribe special eye drops to dilate (widen) the pupil to allow more light to enter the eye. If your child needs eye drops, make sure you carefully follow the instructions for putting them in.

Serious cataract

If the cataract is more serious, your child will need surgery to remove it. Cataracts cannot be removed with medication or lasers.

Why it is important to have surgery to remove a serious cataract

Surgery is important because it will allow your child's vision to develop as normally as possible. It is especially important for children aged under 9 because their vision is still developing.

If your child has a cataract and he is aged under 9, there is a risk that he will develop amblyopia if the cataract is not removed. Amblyopia is sometimes called "lazy eye" and can occur when the affected eye does not get enough stimulation from light rays.

All children aged under 9 should be operated on as soon as possible, whether they are born with a cataract or develop one later. If your child develops a cataract when he is aged 9 or over, the timing of the surgery is more flexible because his vision has fully developed.

What happens during cataract surgery

Before the surgery, your child will have special drops to dilate (widen) the pupil of the eye. These drops sting at first but only for about 10 seconds. They may need to be repeated once or twice.

The eye drops are usually applied right before the surgery in the hospital. If your child needs them before then, your eye doctor will give you a prescription for the drops and explain when to start putting them in.

Your child will have a special "sleep medicine" called a general anaesthetic for the surgery. This will make sure he sleeps through the operation and does not feel any pain.

The surgeon takes out the cataract by removing the lens of the affected eye(s). Your eye doctor will tell you before the surgery if it is best to remove the whole lens or only part of it.

The surgeon will use special stitches to repair the eye wound. These stitches are absorbable, meaning that that they do not need to be taken out. They will dissolve on their own over the first six to eight weeks after surgery.​

In young children with cataracts in both eyes, surgery is often done on the second eye as soon as possible after the first eye. This is to make sure that the vision in both eyes develops evenly.

At times, surgery may be done on both eyes on the same day. Your eye doctor will explain exactly when your child will have surgery and, if it applies, when each eye will be done.

The operation is usually done as a day surgery if your child is over 12 weeks old. If your child was born prematurely or if the surgery is within the first 12 weeks of life, he will usually stay in the hospital overnight.

What to expect after the surgery

Eye patch and shield

Immediately after surgery, an eye patch will be placed over the operated eye. The eye patch is covered with a plastic or metal shield for protection. Your child's patch will be removed the next day by his ophthalmologist when he returns to the eye clinic. If the patch comes off at home, you can leave it off, but make sure you put the eye shield back on.

Your child will continue to wear the shield over the operated eye to protect it while he is sleeping. Your doctor will tell you when your child can stop wearing the shield.

Pain or discomfort

Your child may experience some pain or discomfort in the operated eye. Please ask your doctor what medication you can give your child at home to relieve the discomfort or pain.

The nurses in the recovery room will watch your child for signs of pain or discomfort and will be able to give medication if your child needs it. 

Before your child is discharged from hospital, please ask the nurse when your child last had any pain relief medication. This way, you can monitor your child's pain and give medication safely as needed.

Redness, swelling, and discharge

The operated eye will be red and slightly swollen after the surgery. It will also produce a clear discharge. These should decrease over the next few days.

Blurred vision

Without the lens, your child's eye is no longer able to focus clearly, but be assured that your child will not be blind. Objects will be very blurry at first until your child receives a corrective device to improve his vision. You can read more about corrective devices below.

How to care for your child after cataract surgery

Antibiotic and cortisone drops

Sometimes the doctor will order antibiotic drops or a combination of antibiotic and steroid drops for the operated eye(s). Your child may also need to have eye drops or ointment to keep his pupil dilated. If your child needs eye drops, your child's doctor will let you know. Please follow any instructions for applying the ointment or putting in the eye drops​ correctly.

Day-to-day activities

The surgeon who operated on your child will give you instructions about how else to care for your child after surgery. You will need to know, for example, how soon your child can return to normal activities, whether he can have a bath or a shower and when he can return to school or day care.

Use this section to write down the instructions from the surgeon.

Allowed activities: 




Bath or shower instructions:


When your child can return to school or day care:


Other questions you want to ask:


When to call your doctor

Call your doctor immediately if:

  • your child feels more pain or sensitivity to light
  • your child's eyelid becomes redder or more swollen from day to day
  • your child complains of or shows any signs of decreased vision
  • there is any yellowish or greenish discharge from the eyes
  • your child shows any other changes that concern you.

Follow-up appointments after cataract surgery

Follow-up appointments are as important as the surgery itself. These appointments are usually scheduled:

  • 1 day after surgery
  • 1 week after surgery
  • 4 weeks after surgery.

Every time the eye doctor sees your child, he or she will tell you when to come back again.

It is very important to keep these appointments.

Write the date and time of the first appointment here: ______________________

Corrective devices after cataract surgery

A corrective device is something that your child wears to repair his vision. Before the surgery, your child's ophthalmologist will discuss the best device for your child. The main options are:

  • contact lens
  • intra-ocular lens
  • eye glasses.

Your child's eye may also need to be patched. Patching is described in the next section.

Contact lens

A contact lens is an artificial lens made of special material, which can be either soft or hard. It is placed on the child's eyeball.

Once your child's eye has healed enough, he will be fitted for a lens, usually in the eye clinic. Sometimes a child will need to be sedated (calmed with medicine) for the fitting or may even need a general anaesthetic.

The eye doctor will start the fitting by putting an anaesthetic drop in the operated eye.

The doctor will then place a sample contact lens on the eyeball and measure the child's contact lens prescription for strength and fit. Your doctor will explain the strength of contact lens your child is prescribed and the reason for it.

The eye doctor or your optician or optometrist (where you buy the contact lens), will teach you how to insert and take out the contact lens as well as how to clean and store it. Make sure you understand these instructions.

Your child's vision will need to be checked regularly (by an ophthalmologist) with the contact lens on. Because your child's eyes are still growing, he will get a new prescription to adjust the contact lens strength and fit.

Younger children may be prescribed glasses to wear as a back-up when not using the contact lens. Older children may need glasses or bifocals in addition to their contact lenses.

Although it might seem like a major change, babies and children adjust to contact lenses more quickly than adults do.

Intra-ocular lens

An intra-ocular lens is an artificial lens placed in the eye. Most times this is done during the surgery to remove the lens, but it can sometimes be done later. If your child needs this type of lens, the doctor will tell you when it will be fitted.

Unlike the normal lens in the eye, an intra-ocular lens does not change its focusing power. Your ophthalmologist will decide what power of intra-ocular lens your child needs.

Your child may also need bifocal eye glasses. Your doctor will discuss this with you.

Eye glasses

Eye glasses are prescribed only if no other device is suitable. Th is because the lenses are thick and would distort, or interfere with, your child's vision and the glasses feel heavy to wear. However, the vision will develop with glasses just as well as with another corrective device.

If a baby needs eye glasses, the prescription will be for near vision, as he spends his waking hours focusing on things up close (for example food, toys, or a parent's or caregiver's face).

When the baby gets older and needs distant vision, he will get a prescription for bifocals (lenses that allow the eyes to focus on things that are close and far away).

Remember to have regular check-ups

Whatever corrective lens is prescribed, your child will still require regular check-ups with the ophthalmologist. Please call your eye doctor between appointments if your child develops:

  • any discomfort or pain
  • discharge, redness or swelling of the eye
  • decrease in vision
  • any unusual signs or symptoms.

Eye patching

When a child has cataract(s), the vision in the affected eye does not develop properly, which can lead to amblyopia.

If there is any difference in vision between the eyes, even if both eyes were operated on, the doctor will order an eye patch. Blocking the vision of your child's stronger eye with a patch will help to strengthen the weaker eye.

If your child's eye needs patching, your eye doctor will explain:

  • which eye needs to be patched
  • how long and how often your child should wear the patch
  • when a follow-up appointment is needed to check your child's vision.

Long-term effects of cataract surgery

Scar tissue or slight cloudiness

Cataracts do not re-appear after surgery, but sometimes the lens capsule may develop scar tissue or slight cloudiness. If this happens, your eye doctor will explain how it will be treated.

Other eye conditions

Even after patching, and being fitted with a corrective device, your child may develop other eye conditions after surgery. These include strabismus, inflammation (irritation or swelling), glaucoma, and retinal detachment. 

You will need to take your child for regular check-ups to let the eye doctor monitor your child's vision closely and check for any of these conditions as early as possible. It is important to keep all your follow-up appointments.

If you have any questions or concerns, please call your child's eye surgeon. Please write the surgeon's name and phone number here.

Doctor: ________________________   Phone: _________________________

Key points

  • A cataract is a cloudy area over the lens of the eye. In children under 9, it stops the eye's vision from developing normally and can cause amblyopia.
  • If the cataract is mild, the doctor may decide to prescribe eye drops to make the pupil bigger or not to treat it at all if the vision is not affected. If the cataract is serious, the only way to treat it is to remove all or some of the lens during surgery.
  • After surgery, your child will need a corrective device such as a contact lens, intra-ocular lens, or, in rare situations, eye glasses. Your child will also need to wear a patch to help both eyes develop equally strong vision.
  • Your eye doctor will need to check your child's vision regularly after surgery. It is extremely important that you keep all follow-up appointments.
  • Please call the eye doctor if your child has increased pain, swelling, or sensitivity to light after surgery or if his corrective device causes any redness, swelling, discharge, pain, or other unusual symptoms.

Yasmin Shariff, RN
Asim Ali, MD, FRCSC
Nasrin Najm-Tehrani, MD, FRCSC
Kamiar Mireskandari, MD, FRCSC​


​At SickKids:

If the eye doctor who operated on your child's eye(s) is not available, call 416-813-7500 and ask for the eye doctor on call.​