Amblyopia is the medical term for lazy eye — a problem with vision where the eye and brain do not work together properly. The brain favors one eye over the other, and the weak eye does not move or focus correctly.
Amblyopia is the most common cause of sight problems in children, but it can occur in adults as well. There are several types of amblyopia and many ways to attempt to improve your vision using eye exercises.
What Is Amblyopia?
When you ask for an amblyopia definition, most people will just say it’s a lazy eye: one eye not moving, focusing or seeing as well as the other. This covers the basics of amblyopia, but it’s not the full story.
Amblyopia is the medical term for lazy eye. However, the lazy eye can still move in alignment with the stronger eye. Amblyopia happens when one or both eyes does not develop clear vision, and the brain starts to ignore the information coming from the bad eye. About 3 percent of kids have amblyopia, and it usually develops before the age of 2. It can occur any time up to age 8, however.
According to the American Academy of Ophthalmology, there are several amblyopia types: (1)
- Refractive amblyopia: This is the most common form of amblyopia. Refractive errors happen when the eye’s shape keeps light from focusing correctly, often causing blurry vision.
- There are two subtypes: anisometropic and isoametropic. Anisometric amblyopia means you have one lazy eye, caused when each eye has a unique refractive error. Isoametropic amblyopia means both eyes have trouble focusing and communicating with the brain. This happens when the refractive errors are significant and fairly similar in both eyes.
- Strabismic amblyopia: When one eye is constantly turned, the brain may start to ignore the information coming from that eye. This type is basically crossed eyes plus a lazy eye.
- Deprivation amblyopia: When an eye has physical problems that impact vision, amblyopia can develop. This is usually the most serious form and can lead to permanent vision loss.
- Reverse amblyopia: Sometimes, the good eye can develop amblyopia when you get treatment for the bad eye. While the good eye is “penalized,” it may develop vision problems and may then be ignored by the brain.
- Eye alignment
- Strabismus, better known as crossed eyes, happens when the eyes don’t look at the same place at the same time.
- Amblyopia happens when the vision doesn’t develop correctly and the brain ignores input from one eye. You can’t tell if someone has amblyopia just by looking at them, since it doesn’t always cause eye wandering.
- Vision problems
- Strabismus results from different alignment in the eyes — a problem with “eye teaming.” The brain may have trouble combining two different images, even if they are clear. This can lead to the brain ignoring the image from the turned eye, resulting in amblyopia.
- Amblyopia involves poor vision development in at least one eye, since the light doesn’t focus correctly to help form a clear picture. The brain starts to ignore the image from the eye that has trouble focusing.
- Strabismus can lead to amblyopia. If left untreated, it can cause vision problems and even permanent vision loss.
- Amblyopia can also lead to permanent vision difficulties if not treated early.
- Strabismus treatment often includes eye exercises, glasses or contacts and even surgery to align the eyes.
- Amblyopia treatment may include correction of strabismus, glasses or contacts, patching or eye drops and other eye therapies to improve eye teaming.
What is amblyopia in adults?
Amblyopia in adults is the same as amblyopia in children: lazy eye. It may have been present since childhood and not detected until adulthood, or it may result from something in adulthood, such as trauma or vision damage. It causes vision loss in about 2.9 percent of adults, according to the Mayo Clinic. (4)
Can amblyopia be corrected?
In most cases, amblyopia can be effectively treated. If not treated before 8 years of age, however, vision improvement may be minimal. Some people do see improvement in vision even when treated at older ages, while others may have permanent vision loss. (5) LASIK vision correction may be offered for certain cases of amblyopia. However, many doctors will not perform LASIK if your weak eye cannot achieve near-perfect vision after correction.
Signs and Symptoms
Amblyopia symptoms can be hard to detect, since some people with lazy eye don’t have crossed or wandering eyes. If one eye has good vision, children can usually compensate for the other eye’s poor sight, making it hard to know about amblyopia, especially if they are too young to mention it.
You may not know you or your child has lazy eye without an eye exam. Even if you suspect you have it, an eye exam is required to diagnose it and to identify the cause of the vision problem.
Signs and symptoms of amblyopia include: (4, 5, 6)
- A wandering eye or an eye that does not move well with the other
- Bumping into things
- Poor depth perception
- Squinting or tilting the head
- Blurry vision
- Double vision
- Covering or shutting one eye
- Eye strain
Causes and Risk Factors
Amblyopia causes can include anything that forces you to rely on one eye more than the other. In many cases, lazy eye is caused by: (6)
- Strabismus or crossed eyes
- Different vision ability in each eye
- Vision problems such as nearsightedness, farsightedness and astigmatism
- Damage to an eye from a scar, ulcer, cataract, trauma, surgery or disease (such as glaucoma)
- Eye patching
- A droopy eyelid (also called ptosis)
- Vitamin A deficiency
Risk factors for amblyopia include: (4, 7)
- A family history of lazy eye
- Premature birth or small size at birth
- Developmental disabilities or genetic disorders that affect the eyes
- Patching an eye
- Eye injury or surgery
- Childhood cataracts or glaucoma
- Eyelid tumors
Is amblyopia a genetic disease?
Genetics are not the only cause of amblyopia, but heredity can play a role in the condition. You are more likely to develop the problem if you have a family history of lazy eye and vision problems. You are also more likely to develop lazy eye if you have genetic conditions that involve vision or structural eye problems.
Treatment for amblyopia is very important. The sooner it is detected and treated, the better the chance of fixing vision problems. If amblyopia is not treated by the time the eyes are done developing — usually about the age of 8 or 9 — lazy eye can result in permanent vision loss.
Amblyopia treatment usually includes: (7)
- Correcting problems with the weak eye’s vision with prescription glasses or contacts
- Fixing any structural or health problems that may be causing the poor vision, such as by removing cataracts or treating glaucoma
- Forcing the brain to rely on the weaker eye for vision
- This is often done by patching (covering) the good eye for a portion of the day, every day.
- The good eye may be blurred to force the brain to use the weak eye. Blurring can be done using eye drops (atropine), lenses or a Bangerter filter.
- This often needs to be done for weeks or months, until the weak eye improves.
- Amblyopia surgery may be offered in some cases, if the eyes are crossed or if the child has cataracts or other structural problems with the eye
- If amblyopia is related to a vitamin A deficiency, your doctor may encourage you to take supplements or vitamins to improve vision
Children may not like treatments for lazy eye, since they often feel blinded by patching or lenses. They may feel uncomfortable wearing a patch in front of other people or may dislike the sensation of wearing contacts or glasses. It is important to complete treatment regardless of the temporary discomforts. Your child’s future vision may be on the line. With time, the treatments will also become less difficult and disruptive, as the lazy eye improves.
‘Lazy Eye’ Exercises
When you get treatment advice for lazy eye, the eye doctor may encourage you to do eye exercises. These exercises may improve your weak eye’s ability to move and track with the other eye. While they’re not a magic bullet for how to fix a lazy eye, they may improve the eyes’ ability to work together. The key for improvement is consistency — the exercises have to be done regularly (daily or weekly for months or even a couple of years) and in addition to whatever other therapy your eye doctor recommends for the best results.
Overall, evidence is weak regarding whether eye exercises are effective for reversing amblyopia. However, they can’t hurt, so the risk of adding them to your vision therapy plan is low. (8)
You can ask your eye doctor for suggested eye exercises to add to this list. You can also ask for advice on how often and for how long to do each exercise.
Please note: Most eye exercises should be done while the good eye is patched or covered. This forces you to use the lazy eye to see. In fact, patching can be considered an eye exercise in and of itself, since it makes your brain rely on the weaker eye.
Eye exercises for amblyopia include: (8, 9)
1. Start coloring
Coloring inside the lines while your strong eye is covered with a patch helps force the weaker eye to focus on details and boundaries. Even better, coloring is a simple and enjoyable way to guide the lazy eye toward improved movement, tracking and focus. It can make eye therapy fun for kids who may otherwise not be interested in complicated or boring eye exercises.
- Any coloring book will work to strengthen the lazy eye, as long as you try to stay in the lines
- The greater the detail of the coloring book, the more intense the exercise will be for the weak eye
- Careful drawing (not scribbling) may have similar benefits
2. Do puzzles
Puzzles of any kind can help your weak eye grow stronger when the leading eye is patched. Try actual table-top cardboard puzzles, word puzzles with fairly small print, mazes and activity books.
Anything that requires the eye to focus on words, image details, precise shapes or tracking movement of a pen through specific areas (to circle words or work through a maze, for example) forces your weak eye to work on improving its focus. And again, this type of eye exercise is enjoyable and easy therapy for kids and adults with amblyopia.
Focusing on small letters and moving the eye across a page to read a book, the newspaper, bills, homework or magazine can help your weak eye improve. To force the lazy eye to take the lead, try reading with the strong eye patched or covered with your palm.
If you find it too difficult to read small print with your weak eye alone, ask whether your prescription is correct. You may also just need to practice — it takes time and persistence to improve the focus of the weak eye so that it is stronger.
4. Play video games
Yes, you read that correctly. Video games may help improve vision for people of all ages with amblyopia. This approach has surprised many experts, who previously believed that adult amblyopia was difficult or impossible to reverse.
- Studies of specially developed video games for adults with amblyopia have shown the ability to quickly improve vision. (10)
- Even better, off-the-shelf video games may have similar benefits. (11) Just be sure to choose something age-appropriate if your child is young.
- Initial studies in children with amblyopia also show that video games in addition to patching are better than patching alone at improving vision. (12)
- More than 40 apps exist for the treatment of amblyopia. Despite the large number of options, very few involved eye care professionals during game development. Since video games have significant benefits for amblyopia, it is possible that apps may offer similar perks. However, the effectiveness of apps has not been well-studied yet. (13)
Studies of video games for amblyopia range considerably (a half hour per week to two hours per day) in how much time participants spend playing the games. Regardless, the benefit seems considerable and may be a much easier way to get your child to do their eye exercises than the rudimentary eye exercises of old!
5. Practice focusing and tracking
Standard eye exercises are the traditional way of improving eye muscle movement and coordination. They are specific routines you can do with the lazy eye to force it through motions and focusing activities. Over time, the idea is that the exercises support and improve the weaker eye’s vision and help your eyes to work together. These should be done with the strong eye covered unless your eye doctor tells you otherwise. If you also have crossed eyes, you can do strabismus eye exercises as well.
Simple eye exercises to improve focusing, tracking and joint eye movements include: (8, 14)
- Changing the point of focus from something near to something far away, and back again.
- The point of focus can be anything. Focus the weak eye on something close, such as your hand. Then look up and away to something across the room or outside the window and wait for it to come into focus. Then look back to the closer item. Go back and forth with the weak eye several times an hour throughout the day.
- Do pencil pushups.
- Hold a pencil at arm’s length at eye level. Slowly move it toward your nose, keeping your weak eye focused on the pencil. Just take care not to bring it toward you with the sharpened pencil tip facing you. Then slowly follow the pencil as you push it out away from your face again. For young children, other small items can work just as well, such as a marker, finger or toothbrush.
- Concentrate on something that is not moving.
- Keep your focus fixed on the object and study it with your eye. Take in the object’s detail, tracing its outlines and features with your weak eye.
- Practice eye movement.
- Trace a figure eight with the weak eye, or start moving the eye up, down, side to side and all the way around in both clockwise and counterclockwise directions. This may help your eye improve its movement and tracking ability.
- Do eye exercises using YouTube videos. (15)
- Thousands of videos exist to help your lazy eye track movement, focus on images and recognize patterns. While evidence is mixed regarding the effectiveness of computer eye training videos and other eye exercises, they are low risk and some people — especially people who do them on a regular basis — find them very helpful in improving vision and focus.
- Amblyopia requires a formal diagnosis from an eye doctor. Do not attempt to self-diagnose the condition, since it can be caused by serious health problems.
- Lazy eye usually requires prescription eyeglasses or contacts and at least one other treatment, such as eye drops, patching or surgery. Do not attempt to self-treat amblyopia without the guidance of an eye health professional.
- Untreated amblyopia can result in permanent vision loss. It is important to follow your amblyopia treatment plan very closely. By not complying, you can put your future vision at stake.
- Amblyopia, also known as lazy eye, results from a vision problem in at least one eye. Over time, the brain ignores the image from the eye that cannot see as well.
- It can happen as a result of crossed eyes as well as other problems, such as glaucoma or simply poor vision (nearsightedness and farsightedness). Amblyopia is the most common vision problem in young children.
- In some cases, amblyopia causes a wandering eye. It can also cause problems with depth perception, headaches and overall vision. However, some people compensate quite well and don’t know they have a problem until they have an eye exam.
- Amblyopia most often affects young children. Provided it is caught and treated by the age of 8 or 9, most people regain full vision. Lack of treatment can result in permanent vision loss. However, even adults with amblyopia can show some improvement with eye therapies.
- Common treatments include patching the strong eye, treating vision or structural problems with the weak eye, using eye drops to blur vision in the strong eye and surgery to treat crossed eyes.