What is Amblyopia?

Another term for amblyopia is lazy eye.

Amblyopia is a condition where the electrochemical connections between the eye and brain do not develop during childhood.  The structures of the eye are normal. The affected eye is commonly called a “lazy eye." 

In other words, light is passing through the eye but because of developmental problems in the brain the visual processing system is not functioning correctly and so vision in the affected eye is not properly focused and is blurry.  Glasses do not help.

Amblyopia begins during infancy and early childhood and in most cases only one eye is affected.

Amblyopia is a common cause of visual impairment in children and affects about two to three out of 100 children.

In many cases, the weaker eye turns outward or inward and, hence, was called "lazy."  Other terms include walleye and squint.

What Causes Amblyopia?

The most common cause of amblyopia is strabismus, which is when the eyes are misaligned.  One eye may be turning in, out, up, down or at an angle. The brain ignores the visual input from the misaligned eye and the vision in that ignored eye becomes worse.

Another cause is the inability of one eye to focus as well as the other. If there are unequal refractive errors between the eyes, called anisometropia, such as one eye that is nearsighted or farsighted while the other eye is not, then the brain will rely on the eye that has less uncorrected refractive error and ignore the vision from the farsighted or nearsighted eye. This type of amblyopia is called refractive amblyopia.

Deprivation amblyopia is caused by something, such as a congenital cataract, that obstructs light from entering a baby’s eye. Prompt treatment of the cataract will allow normal visual development.

Amblyopia Signs and Symptoms

If your child’s eyes are misaligned or crossed it could be a sign of amblyopia. Squinting or shutting one eye when trying to look at something is another sign that the child could have amblyopia.

If you notice these signs have your child’s vision examined as soon as possible.  The longer the brain ignores visual signals from one eye, the condition becomes more difficult to treat.

Amblyopia Treatment

Treatment for amblyopia is simply to force the brain to process the visual signals from the “lazy eye” so that visual processing for that eye becomes stronger. The “forcing” is done with the use of an eye patch or eye drops in the unaffected eye so that the lazy eye and the brain must work at developing the visual processes needed for clearer vision.

If strabismus is the cause of amblyopia sometimes eyeglasses with prism lenses will correct the problem, in other cases surgery to strengthen the eye muscles will be required. If a congenital cataract is the cause of amblyopia removal of the cataract will correct the child’s vision.  

Consult your pediatrician or your eye doctor.