Illustrative stock photograph; not a CEI patient, treatment result or clinic equipment.

Children rarely complain that one eye doesn’t see as well as the other. They simply use the stronger eye and get on with life. That’s why amblyopia, often called “lazy eye,” can go unnoticed until an eye exam picks it up.

Amblyopia is the most common cause of vision loss in children, and it’s very treatable, especially when it’s found early. This guide explains what it is, what to watch for and how it’s treated.

Key Takeaways

• Amblyopia is poor vision, usually in one eye, that develops in childhood when the brain learns to rely on the stronger eye.
• It is the most common cause of vision loss in kids, affecting up to 3 in 100 children.
• Signs can be hard to spot. Vision checks during childhood are the best way to find it.
• Treatment works best when started early and may include glasses, patching or eye drops.

What Is Amblyopia?

A child’s vision develops during the first years of life. To see well, the brain needs clear signals from both eyes. In amblyopia, something interferes with that process, so the brain begins to favour the stronger eye and ignore the weaker one. Over time, vision in the weaker eye doesn’t develop properly.

The name “lazy eye” can be misleading. Children with amblyopia aren’t lazy, and they can’t control how their eyes work. Amblyopia usually affects one eye, but less commonly it affects both.

Signs to Watch For

Amblyopia often has no obvious signs. Parents may notice that a child:

• Squints
• Shuts one eye
• Tilts their head to see
• Has trouble judging how near or far things are (poor depth perception)
• Has an eye that turns in, out, up or down

If one eye is covered and the child becomes upset, tries to peek around the cover or pulls it off, that can be a clue the uncovered eye doesn’t see well. Often, though, parents don’t know until a doctor finds it during a vision check.

What Causes Amblyopia?

Doctors don’t always know the cause. Often, another eye problem leads to amblyopia:

• Strabismus (eye misalignment). One eye turns in, out, up or down. To avoid seeing double, the brain may ignore the turned eye.
• Refractive errors. Nearsightedness, farsightedness or astigmatism that is much stronger in one eye can cause the brain to “turn off” that eye. Because the child sees fine with both eyes open, this type can be hard to notice.
• Cloudiness in the eye, such as a cataract present from birth or early childhood.
• A droopy eyelid (ptosis) that blocks vision in a developing eye.

Amblyopia is more likely in children who were born early, were smaller than average at birth, have a family history of amblyopia, childhood cataracts or other eye conditions, or have developmental disabilities.

Illustrative stock photograph; not a CEI patient, treatment result or clinic equipment.

When Should a Child’s Vision Be Checked?

All children should have their vision checked during routine visits with their family doctor or pediatrician, and many have vision screening at school. The National Eye Institute advises a vision check at least once between ages 3 and 5.

If you, your child’s doctor or the school has concerns, your child should have a full eye exam.

How Is Amblyopia Treated?

Treatment usually has two steps.

1. Treat the underlying problem. This might mean glasses or contact lenses for a refractive error, or surgery for a cataract.

2. Retrain the brain to use the weaker eye. The more the brain uses it, the stronger the vision becomes. Options include:

• An eye patch over the stronger eye. A stick-on patch makes the brain use the weaker eye. Some children need it for about 2 hours a day; others need it for more of the day.
• Eye drops in the stronger eye. A once-a-day atropine drop temporarily blurs near vision in the stronger eye, encouraging the brain to use the other one. For some children, this works as well as patching and can be easier for families.
• Special glasses that blur vision in the stronger eye may be used in some cases.

Vision may start to improve within a few weeks, but the best results usually take months. Some children need treatment from time to time afterward to keep amblyopia from coming back.

Tips for Patching Success

• Use a stick-on patch that fits comfortably, stays firmly in place and doesn’t let your child peek around the edges. Avoid pirate-style patches with elastic or ties, which are easy to remove.
• Make patching part of a daily routine, like brushing teeth.
• Plan fun activities that use the eyes during patch time, such as drawing, puzzles or games.
• Praise effort and consider a reward chart.
• Ask your eye doctor what to do if your child refuses the patch. Drops may be an option.

Why Early Treatment Matters

The sooner amblyopia is treated, the better. Children who grow up without treatment may have lifelong vision problems, and treatment is usually less effective in adults than in children.

Frequently Asked Questions

Will my child grow out of a lazy eye?

Amblyopia doesn’t usually go away on its own. Early treatment gives the best chance of good vision.

Is amblyopia the same as a crossed eye?

Not exactly. A crossed or turned eye (strabismus) is one possible cause of amblyopia, but amblyopia can also happen when the eyes look straight.

Can adults be treated?

Treatment is usually less effective in adults, which is why childhood vision checks matter.

Could laser eye surgery fix amblyopia later?

Amblyopia is treated by helping the brain use the weaker eye during childhood. If you’re an adult with amblyopia and are curious about vision correction, a full assessment can explain what’s realistic for your eyes.

Book Your Consultation

If you have concerns about your child’s vision or an eye that turns, our team can help. Book your consultation: call our Saskatoon office at 306-244-4111, Monday to Friday, 7 am to 4 pm. Conlon Eye Institute is in the Medical Arts Building, 341-750 Spadina Crescent East, Saskatoon, SK S7K 3H3.

References

• National Eye Institute. Amblyopia (Lazy Eye). https://www.nei.nih.gov/eye-health-information/eye-conditions-and-diseases/amblyopia-lazy-eye — supports definition, usually one eye but sometimes both, “not lazy,” most common cause of vision loss in kids, up to 3 in 100 children, signs (poor depth perception, squinting, shutting one eye, head tilt), vision screening at least once at ages 3–5, risk factors (premature, small at birth, family history, developmental disabilities), causes (refractive errors, strabismus, cataract), treating the underlying problem, patching (2 hours a day or more), once-daily atropine drops, improvement within weeks with best results over months, possible ongoing treatment, and lower effectiveness in adults.
• American Academy of Ophthalmology. Amblyopia: What Is Lazy Eye? https://www.aao.org/eye-health/diseases/amblyopia-lazy-eye — supports vision not developing properly because the brain ignores one eye, causes (strabismus, refractive error worse in one eye, cataract, ptosis), hard-to-notice cases when vision seems fine with both eyes, diagnosis by covering one eye and watching the child’s reaction, routine vision checks by family doctors and schools, treatment by patching, blurring drops or glasses with a blurring lens, several months for improvement, possible part-time patching for years, and choosing a comfortable stick-on patch rather than pirate-style patches.

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