Introduction to amblyopia:

Sometimes even children with perfect eyes can't see well. How can this be?

What is amblyopia?

Practice makes perfect. Young eyes need practice in order for mature vision to develop in the brain. For this to happen, a clear image of the world needs to land on the retina and be transmitted to the visual cortex of the brain.

Amblyopia is the loss of vision caused when a clear image of the world is not available on the retina during key periods of development. The visual cortex of the brain develops dramatically in babies and young children. It continues to develop throughout the first decade of life.

Anything that interferes with a normal image on the retina during this time can lead to amblyopia – a loss of vision that continues even if no problem remains in the eye.

Who gets amblyopia?

Amblyopia might occur in strabismus, when one eye deviates to the side and isn’t used as much. It might occur if there is unequal vision in the two eyes from astigmatism, or if one eye is more nearsighted or farsighted than the other. It might occur if there is a cataract blocking vision in one eye, or if there has been an injury.

Whatever the cause, if the “lazy” eye relaxes, the vision in that eye gets worse, and a destructive cycle begins. The initial difference between the eyes does not have to be dramatic.

Amblyopia can also occur if there is a severe blurring of vision in both eyes, as in severe nearsightedness or farsightedness.

Amblyopia only begins during the first ten years of life. It is more likely, and often more serious, the younger the child is when the retina is not receiving a clear image.

What are the symptoms of amblyopia?

Most amblyopia is discovered during routine eye screening – without any symptoms having been noticed. The symptom of amblyopia is decreased visual acuity, but this is not usually found unless the child has her vision checked.

An eye that deviates, cloudiness in one eye, or any signs or symptoms of nearsightedness, farsightedness, or astigmatism might suggest that amblyopia is developing as a result.

Is amblyopia contagious?

No

How long does amblyopia last?

If normal vision is not restored to the eye by about age 6, some degree of vision loss will probably be permanent. Usually a lazy eye should be diagnosed by age 3 in order to restore normal vision to that eye by age 6.

How is amblyopia diagnosed?

A March 2002 policy statement by the American Academy of Pediatrics (AAP) recommends that all babies have vision screening (including screening for strabismus and amblyopia) at the earliest possible age, and at regular intervals throughout childhood. Rather than relying on informal or subjective assessments of vision, the policy discusses photoscreening, a new test that can make checking vision easier and more accurate for even very young babies. A specially equipped camera takes their picture and a computer or a person analyzes the eye data obtained.