Amblyopia

What is Amblyopia?

Amblyopia, or lazy eye, develops when one eye becomes weaker than the other during infancy or childhood. The brain favours the stronger eye, allowing the weaker eye to deteriorate over time. Early screening is important because treatment works best when it starts early. Treatments include patching and glasses.

How does amblyopia affect my child?

In a child with amblyopia, one eye sees a blurred image while the other sees clearly. The brain begins to ignore the blurry eye and relies only on the eye with clear vision. Over time, the brain learns to depend on the stronger eye, and the weaker eye continues to deteriorate.

Who is at risk of amblyopia?

Some children have risk factors that make amblyopia more likely, including:

• A family history of eye problems
• Developmental disabilities
• Premature birth
• A low weight at birth

How common is amblyopia?

Amblyopia is the most common cause of vision loss in children, affecting 2% to 4% of children up to the age of 15. It can be present even when a child shows no noticeable problems, yet it can cause permanent damage if it is not detected and treated during childhood. Early, regular eye examinations are therefore essential.

What causes amblyopia?

Amblyopia occurs when there is a significant difference between the two eyes in their ability to focus, and it most commonly develops as a result of other vision problems. It is important to treat these underlying conditions; otherwise the brain begins to rely on the eye with better vision, and amblyopia takes hold.

What eye conditions may lead to amblyopia?

Conditions that may lead to amblyopia include:

Refractive errors: These affect the way light is focused as it passes through the eye.

• Myopia — difficulty seeing objects in the distance.
• Hypermetropia — difficulty seeing objects up close.
• Astigmatism — an unevenly curved cornea.

Strabismus (crossed eyes): The eyes are meant to move together as a pair, but sometimes they don’t. If one eye drifts — inwards, outwards, up or down — the brain may come to rely on one eye over the other, leading to amblyopia.

Structural problems: Sometimes a structural problem within the eye can lead to amblyopia, including:

• Cataracts, which cause clouding of the lens and blurred vision
• A droopy eyelid
• Corneal scarring

What are the symptoms of amblyopia (lazy eye)?

Amblyopia is not always obvious, and it often goes undetected until a child has an eye examination. That is why every child should have early, regular vision checks.

Even so, you may notice signs at home. A child with amblyopia may:

• Often bump into things on one particular side
• Have a large difference in short-sightedness or long-sightedness between the two eyes.
• Favour one side of the body.
• Have crossed eyes.
• Have a droopy eyelid.
• Shut one eye or squint frequently.
• Frequently tilt their head to one side.

When should amblyopia be diagnosed?

Early diagnosis greatly increases the chances of a full recovery. Athens EyeCare Clinic recommends that children have a thorough vision test before the age of 6 months and again before the age of 3 years.

What tests can diagnose amblyopia?

A paediatrician, a school vision programme, an optometrist or an ophthalmologist can check a child’s vision for amblyopia.

During the check, they may:

• Put drops in the eye to enlarge the pupil
• Shine a light into each eye
• Cover one eye at a time and test whether each eye can follow a moving object
• Ask older children to read letters on a chart across the room

What are the treatments for amblyopia?

Treatment for amblyopia is far more effective when it starts early, while the connections between the eyes and the brain are still developing. The aim is to encourage the child’s brain to use the weaker eye. Options include:

• Eye patches: Your child may wear a patch over the stronger eye for at least a few hours a day. This effective treatment can continue for months or even years. The patch forces the brain to use the images from the weaker eye, gradually making that eye stronger.
• Glasses: Glasses are another common treatment for lazy eye. They help by correcting short-sightedness, long-sightedness and eye crossing.
• Eye drops: In milder cases, your specialist may recommend eye drops (atropine) to temporarily blur the vision in the stronger eye. The goal is the same as with a patch: to encourage the brain to use the weaker eye.
• Surgery: An operation for amblyopia itself is rare. Your paediatric ophthalmologist may, however, suggest surgery to correct certain causes of amblyopia, such as cataracts.

Can I prevent amblyopia?

You cannot prevent amblyopia or the vision problems that may cause it, but you can stop it from getting worse or causing permanent damage. The best way to prevent vision loss from amblyopia is regular eye examinations. Make sure your child has a thorough eye examination by the age of 6 months and again by the age of 3 years.

What is the outlook for people with amblyopia?

With early diagnosis and treatment, children with amblyopia can achieve a significant improvement in their vision. The goal is to improve vision as much as possible, although perfect sight may not always be achievable, particularly in severe cases.

Amblyopia does not go away on its own. Left untreated, it can cause permanent loss of vision and an eye that constantly looks in a different direction.

How can I best take care of my child with amblyopia?

There are several ways you can support a child with lazy eye:

• Eye care: Make sure your child has regular eye examinations — one by 6 months of age and another by the age of 3 — and attends every follow-up appointment.
• Stick with treatment: Encourage your child to wear their glasses or patch, even when they resist. Small rewards, and explaining why it matters, can help.
• Encourage your child to actively use the weaker eye while wearing the glasses or patch — read together or do puzzles.