Amblyopia (Lazy Eye)

Amblyopia, also known as “lazy eye”, is defined as reduced vision in the eye due to the lack of normal visual development. If left untreated, amblyopia can result in severe visual disability in the affected eye.
 

Amblyopia occurs during infancy or early childhood, and it’s estimated that 2 to 3 percent of the U.S. population is affected by some degree of amblyopia.
 

Amblyopia Signs and Symptoms
 

Lazy eye can often be difficult to detect without a comprehensive eye exam, as it typically affects only one eye. In many cases, a child compensates for the blurry eye by relying on the unaffected eye.
 

In order to make sure your child is at no risk of amblyopia, it’s important to schedule their first eye exam at 6 months of age, followed by a second and third exam at the age of 3 and prior to entering school, respectively.
 

A simple at-home test you can try is to cover and uncover your child’s eyes (one at a time) when they are performing a visual task, such as reading or watching television.  If the child is bothered by blurry vision in one eye, it’s possible that the eye is affected by amblyopia.
 

Usually, children with amblyopia don’t mind when their blurry (amblyopic) eye is covered, as they are relying on it to see clearly, but when the good eye is covered and they have to rely solely on the blurry amblyopic eye, this is bothersome.
 

A simple screening test is not enough to determine whether or not your child has amblyopia. Schedule a comprehensive eye exam with your eye doctor to ensure that your child is not affected by lazy eye.
 

What Are The Causes of Amblyopia?
 

There are three types of amblyopia:
 

Strabismic Amblyopia. This is lazy eye caused by misalignment of the eyes (strabismus). To prevent double vision, the visual part of the brain ignores (suppresses) vision from the turned eye, resulting in incomplete visual development in that eye.
 

Refractive Amblyopia. This type of lazy eye is caused by a significant difference in the amount of refractive error (nearsightedness, farsightedness or astigmatism) in the two eyes. In such cases, the brain ignores the more blurred images from the eye with greater refractive error and favors the clearer images produced by the “good” eye that has less refractive error.
 

Deprivation Amblyopia. This is lazy eye caused by something that obstructs light from entering and being focused in a baby’s eye, such as a congenital cataract. Prompt treatment of congenital cataracts is necessary to allow normal visual development to occur.
 

Of the three types, strabismus is the most common cause of amblyopia.
 

Treatment of Amblyopia
 

The treatment method for amblyopia depends on the cause. If lazy eye is detected early and promptly treated, the better the chances are that the affected eye will develop normally.
 

Treating Strabismic Amblyopia
 

Successful treatment of strabismic amblyopia in most cases requires the eyes to first be properly aligned through surgery.
 

Once the eyes are surgically aligned, part-time patching of the unaffected eye helps to improve vision in the amblyopic eye. A program of vision therapy is often recommended after strabismus surgery to help the two eyes get adjusted to working together to produce a clear, comfortable binocular vision and normal depth perception.
 

Treating Refractive Amblyopia
 

Correcting refractive amblyopia involves fully correcting the refractive error in both eyes. Because eyeglass lenses sometimes cause unequal magnification of images when the refractive error is significantly different in both eyes, contact lenses are often a better solution than glasses.
 

Following the full correction of refractive errors in both eyes, putting an eye patch on the good eye will help stimulate improvement of visual acuity in the amblyopic eye. Your eye doctor might also recommend a program of vision therapy to make sure both eyes get adjusted to working together.
 

Treating Deprivation Strabismus
 

When congenital cataracts occur from deprivation amblyopia, surgery to remove the cataracts should be performed as soon as possible to prevent permanent vision loss. A pediatric ophthalmologist who specializes in cataract surgery for infants and small children should be consulted.
 

Following cataract surgery, contact lenses, eyeglasses, patching and/or vision therapy may be needed to fully correct the refractive error in both eyes.
 

Alternatives to Eye Patches
 

Most children dislike the idea of having to wear an eye patch during amblyopia treatment, not only because of the blurry vision but because an eye patch can draw unwanted attention.
 

Fortunately, there are alternatives (although more expansive) to wearing an eye patch. Your eye doctor can prescribe occlude contact lenses to wear on the good eye instead of an eye patch. This specialty lens contains an opaque tint in the center, which blocks light from the pupil. This can be worn without noticeably affecting your child’s appearance.
 

Another alternative to eye patching is eye drops that cause temporary blurring of the good eye. Your eye doctor can discuss both options with you if you feel your child shouldn’t wear an eye patch.
 

The Best Treatment is to Take Action As Soon As Possible
 

If promptly detected before the ages of 8 to 9 and properly treated, the affected eye will be able to develop into 20/20 vision.
 

Give your child the best vision possible and schedule an early childhood eye exam.