What Nearsightedness,
Farsightedness and Astigmatism Really Mean In The Eyes Of Children
Farsightedness,
nearsightedness and astigmatism. Everyone has heard the terms, but parents
want to know what they mean and how they differ in order to understand
the treatment for their child's eyes. The American Association of Pediatric
Ophthalmology and Strabismus (AAPOS) offers simple explanations for
hyperopia (farsightedness), myopia (nearsightedness) and astigmatism.
Hyperopia
(farsightedness) means the eyes are out of focus more for near than
for distance. A very farsighted child may have blurred vision at distance
and at near. A mildly farsighted child may actually see completely normal
at distance and near, but will compensate for the farsightedness by
focusing or "accommodating", which a child can do to a much
larger degree than an adult. In addition, a moderately farsighted child
may see well at distance and near but experience eyestrain or crossed
eyes when focusing (accommodating) to compensate for the uncorrected
need for glasses.
On the
other hand, myopia (nearsightedness) means the eyes are out of focus
more for distance than for near. If a child is very nearsighted, things
will be blurry both at distance and at near. Some children are extremely
myopic (nearsighted) at a young age. By age two or three, they will
be sitting very close to the TV and holding objects up close to their
face. These children usually take readily to glasses and like to wear
them without much adjustment.
The most
common form of nearsightedness, where vision is better at near than
distance, does not begin until about age five to seven or sometimes
later. Nearsightedness usually increases in amount every year as the
child grows, with the greatest changes occurring between ages 6 and
12, but many continue to become more nearsighted as teenagers. In general,
the earlier the nearsightedness begins, the more nearsighted the child
will become.
If a child
is only slightly nearsighted, it may be best to avoid glasses and obtain
another eye exam in six to twelve months. Children who see clearly at
near but require glasses for small amounts of nearsightedness should
remove them for reading or other up activities. However, children who
are significantly myopic will need glasses for most or all activities.
In the
past, dilating eye drops, bifocals or hard contact lenses have been
used to treat nearsightedness; today only refractive surgery, such as
LASIK, is the only type of therapy available to actually eliminate nearsightedness.
These types of surgery are generally not done in children because their
eyes have not yet finished growing. The eye normally stops growing by
about 18 to 21 years of age. A few children have undergone these procedures,
but most children's nearsightedness is best treated with glasses or
contact lenses.
The term
astigmatism means that the eye is shaped oval like a football instead
of the normal round shape like a basketball. Infants often have small
or even moderate amounts of astigmatism that may simply disappear and
need no treatment. Children, ages one to three, who have large amounts
of astigmatism will need to wear glasses. Others with only small amounts
of astigmatism may not require glasses at all. Sometimes the astigmatism
goes away by itself, but other times glasses are needed at an older
age for reading and schoolwork. If the astigmatism is very large or
greater in only one eye, glasses may be needed during all waking hours.
Glasses
do no make astigmatism disappear, and they do not change the shape of
the eye. Glasses only bend the incoming light to correct misshapen eyes.
The eye undergoes natural slight changes in shape with age and astigmatism
may increase or decrease in amount depending on the growth of the eye.
Since the
vision problems of children are far different from adults, a pediatric
ophthalmologist is best qualified to determine a child's need for glasses.
A pediatric ophthalmologist is an Eye MD (an eye physician and surgeon)
who specializes in children. A pediatric ophthalmologist graduated from
medical school and completed a three or four-year approved ophthalmology
residency program training in all aspects of eye disease. In addition,
this type of physician received further training in an approved fellowship
program dedicated to the study of eye diseases and disorders of children's
eyes such as hyperopia, myopia, astigmatism, strabismus and amblyopia.
Pediatric ophthalmologists who are members of AAPOS have demonstrated
high qualifications in the proper treatment and care of children's eyes.
It is extremely
important that children be prescribed the appropriate glasses so they
will develop normal vision while they are still growing. Some children
require glasses for all waking hours, while others whose eyes are only
slightly out of focus may be best served by not wearing them at all.
Children's glasses can be very expensive, for a two year old could easily
need new glasses every two to three months at $150 or more per pair.
The skill of the eye examiner, combined with frequency and costs of
glasses, should be considered when searching for the best person to
examine a child's vision.
Considering
that the life expectancy of a child born today is probably about 90
years, an early eye exam or screening test is an excellent investment
for life. Most parents will have already their child's teeth checked
by age three or four. An eye exam for children is just as important,
for unlike teeth, eyes cannot be replaced.
For more
information, visit the AAPOS website at http://med-aapos.bu.edu.
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