Amblyopia (Lazy Eye)

What Is Amblyopia or Lazy Eye?

Amblyopia, often called “lazy eye”, is the leading cause of vision loss in children, with three to four out of every 100 children experiencing it. It occurs when images from one or both eyes are ignored by the brain due to being blurry, of poor quality, or because the eyes are misaligned.

If this continues uncorrected, the nerve pathways between the eye and the brain can deteriorate to the point where the brain only sees blurry images from the affected eye, even with prescription eyeglasses or contacts. Untreated, amblyopia can cause permanent vision loss and lead to deficits in depth perception and peripheral vision and leave the child vulnerable to a visual disability, especially if the good eye is injured or becomes diseased.

What Causes Amblyopia?

Vision development occurs during infancy and young childhood as vision centers in the brain develop in response to visual stimuli. If an infant or young child is not able to see clearly, normal development of the vision centers may be impaired and lead to amblyopia.

Common causes of poor vision that can lead to amblyopia include:

• Uncorrected refractive error, such as nearsightedness, farsightedness, or astigmatism
• Misalignment of the eyes, known as strabismus
• Pediatric cataract
• Pediatric ptosis or drooping eyelid

Common Amblyopia Symptoms

The symptoms of amblyopia are not necessarily easy to detect. While significant eye misalignment from strabismus or a drooping eyelid is very noticeable, other indicators can be harder to notice, and may include:

• Squinting
• Closing one eye
• Bumping into things or misjudging the distance of objects
• Tilting of the head to one side to look at an object

In many instances, parents find out their child has amblyopia only after it is diagnosed by an eye doctor during an eye exam.

How Is Amblyopia Diagnosed?

Detection of amblyopia typically begins with the set of standard vision screenings that occur from birth through early childhood, usually performed by a pediatrician or family doctor. One of the most important of these screenings is the “red reflex” test. This is used to detect cataracts or other conditions that can impair vision in newborns, infants, or toddlers.

Infants and toddlers are also checked for their ability to track objects. Once a child is old enough to identify shapes or letters, an eye chart can be used to test visual acuity. Should any of these screenings indicate a problem, a child is referred to a pediatric ophthalmologist who can perform a comprehensive pediatric eye examination to determine if amblyopia is present, and what underlying issues are causing it.

Even if your child passes the initial screenings as an infant or toddler, amblyopia can still develop when they are older. Therefore, we strongly advise you to have your child’s eyes examined by a pediatric ophthalmologist at least once between the ages of three and five in order to detect amblyopia or other pediatric eye conditions while the child is still young enough to respond to treatment.

Amblyopia Treatments

Treating amblyopia often begins with addressing the underlying cause. For instance, if refractive error is the issue, your pediatric ophthalmologist may first prescribe eyeglasses or contacts. If your child has a cataract, it will need to be removed.

When only one eye is affected, the child will typically need to retrain his or her brain to use the weaker eye. The two most common ways to do this are by either covering the dominant eye with a patch or by blurring vision in the dominant eye by using special drops. These simple methods force the brain to accept visual input from the weaker eye, which strengthens it.

Adhesive, disposable eye patches similar to a Band-Aid are commonly used. They come in different sizes for growing children and can be worn for the number of hours per day prescribed by your doctor. For children who wear eyeglasses, different types of patches are available.

Some doctors and parents find the use of atropine eye drops, which blur vision, to be a better alternative to an eye patch. This can be especially true with very young children who may struggle to keep a patch on.

Whichever method is used, vision can start to improve in a few weeks, but it can take months to achieve optimal results. In addition, treatments may be needed periodically over time to keep the amblyopia from returning. Keep in mind that the earlier in life treatment begins, the more likely it is to be successful and that those who grow up without treatment may suffer a lifetime of vision problems.