Table of Contents
20/20 Vision?
Q. What does 20/20 vision
mean?
A. 20/20 vision is a term used to express normal visual acuity (the
clarity or sharpness of vision) measured at a distance of 20 ft. If you have
20/20 vision, you can see clearly at 20 ft. what should normally be seen at
that distance. If you have 20/100 vision, this means that you must be as close as
20 ft. to see what a person with normal vision can see at 100 ft.
Q. Does 20/20 mean perfect vision?
A. No. 20/20 vision only indicates the sharpness
or clarity of vision at a distance. There are other important vision skills,
such as peripheral awareness or side vision, eye coordination, depth
perception, focusing ability, eye-muscle action and others that contribute to a child's
overall vision ability.
Q. Is 15/15 vision better that 20/20 vision?
A. No. 15/15 vision means normal sharpness of vision at 15 ft.
just as 20/20 indicates normal acuity at 20 ft. For consistency, optometrists in the
U.S. use 20 ft. as the standard to express sharpness of vision. Other
countries express visual acuity in their own way. In Britain, for example,
optometrists express visual acuity in meters (6/6 is considered normal acuity).
Q. Why do some individuals have
less than 20/20 vision?
A. Visual acuity is affected by many factors. Less
than optimum clarity may result from vision conditions such as nearsightedness,
farsightedness, astigmatism, amblyopia or other vision problems such as eye
disease.
Q. Can clarity of vision vary with
distance?
A. Some children can see well at a distance but are unable to
bring nearer objects into focus. This condition can be caused by farsightedness or
certain focusing problems. (In mature adults, the loss of focusing ability
is known as presbyopia, and is a natural consequence of the aging process.)
Other children can see items that are close but cannot see objects that are far
away. This condition is known as nearsightedness.
Q. If a child's vision is less that optimum, what
can we do?
A. A thorough examination by a doctor of optometry should identify those
causes, if any, that are affecting a child's ability to see well. In most cases,
your optometrist can prescribe glasses (including bifocals), contact lenses
(when appropriate), or a vision therapy program that will help to improve your
child's vision.
Bifocals and Children's Vision
Care
Q. What are bifocals?
A. Bifocals are
eyeglasses that contain two vision correcting prescriptions within each lens.
They are prescribed when an individual needs different strengths of vision
correction in order to see clearly at both near and far distances. They are
typically prescribed for persons who are over forty whose ability to focus on
close objects has declined due to
presbyopia.
Bifocals are, however, sometimes prescribed for children and teens.
Q. Can bifocals help children and
teens?
A. Although bifocals are most often prescribed for patients over 40, it
is not uncommon for doctors of optometry to prescribe bifocals for children and
teens. This occurs because bifocals may provide the best solution to a
youngster's vision problem.
Q. What are some specific reasons that
children and teens need bifocals?
A. Bifocals are prescribed for younger
persons to correct poor visual acuity (clarity of vision) at various distances.
A common use is for nearsighted persons who need a stronger prescription to see
clearly in the distance than up close. They are sometimes recommended to reduce
the amount of stress placed on the eyes during close work to try to prevent the
development or the further progression of nearsightedness. They may also be
prescribed to help a child learn to focus and aim the eyes correctly. Some
children may exhibit symptoms of strabismus (crossed-eyes) when looking at very
close objects. In this instance, bifocals may be used to help the eyes learn to
aim correctly.
Q. Aren't bifocals for children a sign
of bad eyesight?
A. A young person's need for bifocals does not necessarily
mean very poor eyesight. Rather, it means that the child was fortunate enough to
have a thorough vision examination of his or her overall vision needs and, that
if the proper correction for distance and for near vision is not the same,
bifocals may be the most convenient way of providing both
prescriptions.
Q. What types of bifocals are
available for my child?
A. A bifocal lens generally consists of two vision correcting
segments and the shape and size of each can vary widely. Some have very small
near vision segments while others are split in the middle containing an equal
portion of each. There are some types of bifocals that gradually change in power
from the distance vision segment to the near vision segment, eliminating the
tell-tale line in the middle. These are known as progressive addition lenses
(PAL's). Your doctor will review your child's specific vision needs and will
recommend the type of bifocal that will best meet those needs. Since there
are quite a number of factors involved in the wearing of bifocals, it is best to
follow your doctor's advice.
"X-tra" Questions About Bifocals
for Children and Teens...
Q. Will my child have difficulty adapting to bifocals?
A. With proper parental encouragement, most children adapt to wearing
bifocals quite easily. Actually, children and teenagers generally have fewer
problems than adults in adapting to bifocals.
Q. How long will they have to be
worn?
A. Depending on the vision condition, the need for bifocals can
sometimes be eliminated. If the bifocals are prescribed to help a child's eyes focus
and aim correctly, they may not be needed if these skills improve as the child
grows older. In cases where the bifocals are needed to correct visual acuity,
however, they may have to be worn indefinitely.
Q. How will bifocals affect my child's lifestyle?
A. Once your child has adapted to wearing bifocals, they should not
significantly affect his or her lifestyle at all. Your child's interest in
school, sports, and other endeavors may even improve because of the child's
ability to see better and easier than before.
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