What is amblyopia?

Amblyopia, also known as 'lazy eye,' is a vision disorder that occurs - usually in childhood - when the brain ignores input from one eye. This can happen when the two eyes have different refractive errors or when one eye is turned in or out.

As the brain receives different visual information from each eye, it learns to ignore the input from the weaker eye. This leads to reduced visual acuity in that eye. If left untreated, amblyopia can lead to permanent vision loss in the affected eye.

Amblyopia can often be treated with glasses, by patching the stronger eye, or often a combination of both. It is important to diagnose and treat amblyopia as early as possible - ideally before the age of six - to maximize the chances of successful treatment.

 

" The treatments for amblyopia are generally very effective if the condition is detected and treated early. Most children will have good vision in each eye in the long-term."

RNIB Amblyopia Factsheet

Symptoms of Amblyopia

Amblyopia typically does not cause any noticeable symptoms in the affected eye, which is why it is often called 'lazy eye'. However, some signs that may suggest the presence of amblyopia include:

• Poor depth perception or difficulty judging distances
• Squinting or closing one eye
• Tilting or turning the head to see objects better
• Poor performance in school or difficulty with reading
• Abnormal alignment or movement of the eyes
• Headaches or eye strain, especially after reading or other visually demanding activities

If you or someone you care for is experiencing any of these symptoms, it's important to see a qualified optometrist or ophthalmologist for an evaluation.

It is important to note that some of these symptoms can also be caused by other vision problems, so a comprehensive eye exam by a qualified orthoptist, optometrist or ophthalmologist is necessary for an accurate diagnosis of amblyopia.

Early diagnosis and treatment of amblyopia can help prevent further complications and improve vision.

How someone with Amblyopia might view the world  

Please note this is a simulation of amblyopia, based on the anecdotal experiences of people who have the condition.
This image is not the experience of everyone with amblyopia and is for illustration purposes only.

Diagnosis of Amblyopia

To diagnose amblyopia, an orthoptist or opthalmologist will typically perform a comprehensive eye exam which includes the following:

A visual acuity test

This measures how well each eye can see letters and shapes from a distance. usually using an eye chart.

Refraction test

This determines if there is a need for glasses or contact lenses, to correct any refractive errors that may be contributing to amblyopia. It measures the refractive error (i.e. short / nearsightedness, long / far-sightedness, or astigmatism) of each eye.

Binocular vision assessment

This checks how well the eyes work together to perceive depth. It will also check the alignment of the eyes and the eye movement. 

Ocular health evaluation

This examines the eye's internal and external structure, to detect any signs of eye disease or injury. 

If amblyopia is suspected, the optometrist or ophthalmologist may also perform additional tests to confirm the diagnosis and determine the severity of the condition. This might include techniques such as using eye drops to dilate the pupils and temporarily blur the vision in the better eye, to encourage the weaker eye to work harder.

Early detection and treatment are essential for the best possible outcome. So it's important to schedule regular eye exams for children, especially if there is a family history of amblyopia or other vision problems.

What causes Amblyopia?

Amblyopia often develops due to other eye or vision problems. These are some common eye conditions which might result in amblyopia developing in childhood:

Strabismus

Strabismus - also known in the UK as a 'squint', or in the US as 'crossed eyes' is where the eyes point in two different directions. One eye may be focused straight ahead while the other turns in, out, up, or down. To avoid double vision, the child's brain ignores the image from the eye that is not focused straight ahead. However, this can result in the non-dominant eye not developing properly, resulting in Amblyopia.  

Refractive errors

Having a refractive error means being shortsighted, longsighted or having an astigmatism (blurred vision) If this is worse in one eye, it can be underused, and so vision will not develop properly. This can be difficult to detect, as the child's vision seems fine when they use both eyes.

Cloudiness of the eye 

If born with a cataract - where the lens of the eye is cloudy - vision may not develop properly in that eye.

Droopy eyelid

Ptosis or a drooped eyelid might block a child's vision and so this can impact on the developing eye and lead to amblyopia.

"It is important to diagnose and treat amblyopia as early as possible. Otherwise, a child with amblyopia will not develop normal, healthy vision."

American Academy of Opthalmology

Treatment of Amblyopia

The treatment for amblyopia typically involves correcting any underlying refractive errors such as short-sightedness or long-sightedness (near-sightedness or far-sightedness in the US). This can be done with glasses or contact lenses. The optometrist or ophthalmologist may also suggest 'patching' to encourage the brain to use the weaker eye.

Patching involves covering the stronger eye with a patch for several hours each day. This forces the brain to rely on the weaker eye, which helps to improve vision in the weaker eye and strengthen the connections between the eye and the brain. The length of time a child will need to wear the patch depends on the severity of the amblyopia and the child's age.

In some cases, atropine eye drops may be used instead of a patch. These drops temporarily blur the vision in the stronger eye, encouraging the brain to use the weaker eye.

In addition to patching or atropine drops, vision therapy exercises may also be recommended to help improve eye coordination and depth perception.

Treatment for amblyopia is typically most successful when started before the age of 7 or 8, as the brain's ability to learn and adapt decreases as a child gets older. However, treatment can still be effective in older children and even adults. If you or your child is diagnosed with amblyopia, be sure to follow your eye doctor's recommended treatment plan and schedule regular follow-up appointments to monitor progress.

"Amblyopia starts in childhood, and is the most common cause of vision loss in kids. Up to 3 out of 100 children have it. 

The good news is that early treatment works well and usually prevents long-term vision problems."

National Eye Institute 

Living with Amblyopia

If amblyopia cannot be fully corrected with treatment, it is still possible to live a normal life with the condition. People with amblyopia may have some degree of permanent vision loss in the affected eye, but the brain can learn to compensate for this loss over time. We recommend:

Wear glasses or contact lenses as prescribed

Corrective lenses can help improve vision in the affected eye and reduce strain on the stronger eye.

Use adequate lighting

Good lighting can help improve visual acuity and reduce eye strain. Use a lamp or other light source to enhance visibility when reading or performing other visually demanding tasks.

Be aware of your surroundings

People with amblyopia may have difficulty with depth perception, so be extra careful when walking on uneven surfaces, climbing stairs, or driving.

Attend regular eye exams

Regular eye exams are important to monitor the condition of the eyes and ensure that any changes or new issues are addressed promptly.

Manage other health conditions

Certain health conditions, such as diabetes or high blood pressure can increase the risk of eye problems. Managing these conditions through lifestyle changes or medication can help protect your vision.

Use assistive technology

Assistive technology, including screen magnifiers, screen readers and accessible book readers or text-to-speech software, can help you navigate your daily life in comfort. These tools can make it easier to read, write, study and use technology.

Whatever your experience is with computers, Dolphin assistive technology can help.

Remember, amblyopia is a common condition that can be successfully treated if caught early. By following your optometrist or opthalmologist's recommendations and taking care of your overall health, you can continue to live a full and rewarding life with amblyopia.