What is amblyopia?
Amblyopia is a condition that
occurs in children in whom one eye has poorer vision than the
other. If amblyopia is left untreated, a child's vision will
not develop correctly and as the brain matures, one eye will remain
with poor vision. The brain actually 'ignores' the
image coming from the bad eye, causing the vision in this affected
eye to become even worse and be permanently diminished as the child
becomes a teenager.
Because amblyopia can have serious, permanent effects on your
child, it is important that he or she is regularly tested.
What causes amblyopia?
The most common cause of
amblyopia is one eye having much better focus than the other. For
example, one eye might be very nearsighted or have a lot of
astigmatism, while the other does not. When the child's brain
is confronted with both a blurry image and a clear image, it will
begin to ignore the blurry image. If this goes on for months or
years, the vision in the eye that sees the blurry image will start
to deteriorate even further. Another possible result of the brain
ignoring the poorly functioning eye is a change in the alignment of
the eyes, with the poorly seeing eye turning inward or outward.
This is why amblyopia is sometimes called "lazy eye."
Another condition that can cause amblyopia is called strabismus.
Strabismus or ocular misalignment prevents the eyes from focusing
together on an image. This can cause double vision. In order to
combat this, the child's brain generally chooses to ignore
the image from the deviated eye, causing the vision in that eye to
eventually deteriorate.
Other children cannot see well in one eye because there is
something that blocks light from getting through. This could be
due, among other causes, to a cataract or a small amount of blood
or other material in the back of the eye.
How is amblyopia diagnosed?
Your child's
pediatrician or the vision program at school will check three
aspects of your child's eye health:
- That your child's eyes let light all the way through
- That both eyes see equally well
- That the eyes are moving normally
If there seems to be something blocking the light or if vision
is unequal, or if there seems to be a problem with the movement of
the eyes, the pediatrician or school nurse might recommend a visit
to an eye specialist.