Q. What does 20/20 vision
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
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.
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
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.
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
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.