Patient guide
Lazy eye (amblyopia): what helps in childhood, and later
By Dr. Sam Khoury, Optometrist9 min read
Call the same day for an eye that has newly started to turn in, out, up or down, new double vision, or a white or unusual glow in the pupil in flash photos. You can contact the office at (609) 246-0236. If the office is closed, or you cannot reach us, go to a hospital emergency room — most have an ophthalmologist on call. Double vision together with weakness, numbness or trouble speaking is a 911 call.
Amblyopia, often called lazy eye, is vision that did not fully develop in one eye, or sometimes both, during childhood. The eye itself is usually healthy. The limit is in how the brain learned to use it. That is why glasses can make the weaker eye's picture clear and still not bring it up to the sharpness of the other eye.
This guide covers what causes it, why it is so often missed, how it is treated in children, and the questions teens and adults ask most: whether anything can still be done, how to protect the stronger eye, and what it means for driving, sports and work.
What amblyopia is
Sight is not finished at birth. Through early childhood the brain learns to see by receiving a clear, matching picture from each eye. If one eye sends a blurred picture, or points somewhere else, the brain comes to rely on the other eye and never builds full detail for the weaker one. It is the most common cause of reduced vision in one eye in children, affecting up to 3 in every 100.
Stronger eye. The brain receives a sharp picture and learns to use all of its detail.
Weaker eye. In childhood it sent a blurred picture, so the brain learned to lean on the other eye instead.
The usual causes
- Unequal prescriptionsOne eye is much more farsighted, nearsighted or astigmatic than the other. The eyes look normal, which makes this the kind most often found late.
- An eye turn (strabismus)One eye points in, out, up or down. To avoid seeing double, the brain ignores the turned eye.
- A high prescription in both eyesNeither eye ever had a sharp picture, so both can be affected.
- Something blocking the viewA cataract present from early childhood, or a droopy eyelid covering the pupil. These need prompt care from an eye surgeon.
"Lazy eye" is also used loosely for an eye that turns. The two are related but not the same: a turned eye can cause amblyopia, but many people with amblyopia have eyes that look perfectly straight.
Why it is often missed
A child with one good eye gets around normally and rarely complains. They have never seen any other way, and the good eye does the work. Often the eyes look straight. A school or pediatrician screening checks fewer things than an eye exam, so a child can pass one and still have amblyopia.
Signs that are worth an exam, though often there are none:
- An eye that drifts, especially when your child is tired or unwell
- Covering or closing one eye to look at something, or tilting the head
- Strong objection when the good eye is covered, for example in a game
- A parent or sibling who had amblyopia or an eye turn
We examine children from age five. For a younger child, a practice set up for testing very young children is the better fit, and if you have seen any of the signs above, it is worth booking there rather than waiting.
Treatment in children
Treatment gives the weaker eye a clear picture, then makes the brain use it. It works best the younger it starts, and it usually goes in steps.
- Glasses, worn all day. For many children the glasses alone improve the weaker eye over the first few months, sometimes enough that nothing more is needed.
- Patching the stronger eye for part of the day, so the brain has to use the weaker one. For many children a couple of hours a day is enough; how long depends on how far behind the weaker eye is.
- Or drops instead of a patch. An atropine drop in the stronger eye blurs its near vision for the day. In trials of moderate amblyopia, drops worked about as well as patching, and some children accept them more easily.
- Regular follow-up visits to measure each eye and adjust the plan. When the weaker eye stops improving, treatment is cut back gradually rather than stopped all at once, because vision can slip back.
How much vision improves differs from child to child, and no one can promise a particular result. What makes the biggest difference is consistency: glasses on all day, and the patch or drops on the days they are due.
If an eye turn needs surgery, we refer you to an eye surgeon. Surgery straightens the eye but does not by itself treat amblyopia, so glasses and patching usually continue afterwards.
Teens and adults: can anything be done?
Yes, but what can be done changes with age, and it is worth being clear about it.
Ages 7 to 17
The brain stays adaptable for longer than was once thought. In a large federally funded trial, children aged 7 to 12 often improved with glasses plus patching or drops, even if they had been treated before. In teens aged 13 to 17, treatment helped mainly those who had never been treated. A teenager who was never treated deserves a real trial of treatment.
18 and older
After the late teens, the brain is much less adaptable, and no treatment for adult amblyopia has become standard care. Research with video games or screens that show each eye a different picture, and with repeated vision training, has found small gains in some adults. Results vary, they are often modest, and they cannot be promised.
What is realistic for an adult:
- The full, correct prescription in the weaker eye. If it has never had one, glasses or a contact lens are worth a few months' trial. Sharpness sometimes improves a little, and it is the only way to find out.
- Protecting the stronger eye, which matters more than anything else on this list. See the next section.
- Regular exams of both eyes, so any new problem is found early.
- Knowing the vision rules for any job or license you are aiming for, before you commit to the training.
The weaker eye is not useless. It still adds side vision, and it is a partial backup.
Protecting your stronger eye
This is the most useful advice for anyone with amblyopia, at any age. The stronger eye does most of the work, and if it were injured or developed a disease, the weaker eye would not be a full replacement. Studies have found that people with amblyopia are more likely to end up with serious vision loss in both eyes, mostly because something happened to the stronger eye.
- Impact-resistant lenses. If you wear glasses, have them made in polycarbonate or Trivex, which resist shattering far better than ordinary plastic or glass.
- Sports eyewear for ball and racquet sports, especially basketball, baseball, racquetball and squash. Everyday glasses are not sports protection.
- Safety glasses marked Z87+ for yard work, power tools, hammering, and fireworks.
- Contact lens habits. If you wear contact lenses, an infection in the stronger eye costs you more than it would cost most people. No sleeping or swimming in them.
- Prompt care. A red, painful or suddenly blurred stronger eye should be seen the same day, not at the next routine visit.
Driving, sports and work
Driving
Most people with amblyopia qualify for a regular driver's license, because the standard can be met with the better eye. Commercial truck and bus licenses are different: federal rules set a minimum for each eye separately, with an alternative route for drivers who do not meet it that requires an eye exam report.
Jobs with vision rules
Pilot medical certificates, the military, and some police and fire departments set standards for each eye or for depth perception. Get the exact requirement in writing before you start the training, and bring it to your exam so your vision can be measured against it.
Depth perception and sports
Fine 3D vision, which depends on both eyes working together, is often reduced. Everyday depth judgment also relies on other clues, such as size, shading and movement, so most people with amblyopia drive, park and pour a drink without trouble. Catching a fast ball can be harder, and 3D movies or some virtual reality headsets may look flat. Plenty of people with amblyopia play sports well.
Common questions
I was told it was too late. Is that still true?
For a teenager who was never treated, not necessarily, and it is worth a proper trial. For an adult, large improvement is unlikely, but checking that the weaker eye has its full prescription is still worthwhile, and protecting the stronger eye matters for life.
Will my weaker eye get worse over time?
Amblyopia itself usually stays stable through adult life. Both eyes can still develop the same conditions anyone's can, which is one reason for regular exams. In some people a weaker eye slowly drifts outward over the years; that can be straightened by an eye surgeon if it bothers you.
Can LASIK fix amblyopia?
No. LASIK changes the focus of the eye, not how the brain uses it. Some people with amblyopia can have LASIK to stop wearing glasses, but the weaker eye will not see better than it did with its best glasses. A LASIK consultation covers whether it suits you.
Glasses or contact lenses: does it matter?
When the two eyes have very different prescriptions, glasses can make the image look a different size in each eye, which some people find tiring. A contact lens often avoids that. Either way, the stronger eye needs protection during sports and risky work.
Will my children have it?
A parent or sibling with amblyopia or an eye turn raises a child's chance of having it, so those children should have a full eye exam early, before they start school. We examine children from age five; for a younger child, a practice set up for very young children is the better fit.
Does amblyopia treatment go through my vision plan or my medical insurance?
Visits to diagnose and treat amblyopia are usually medical visits and go through your medical insurance. Glasses usually go through a vision plan if you have one. Call with your plan details and it can be sorted out before your visit.
Book an eye exam
An exam measures each eye separately, checks the prescription and the health of each eye, and looks for an eye turn.
Book an exam Call (609) 246-0236
Khoury Eye Care, Hamilton Mall, 4403 Black Horse Pike, Mays Landing.