Bifocals are lenses that contain two different prescriptions; one for up-close work such as reading and the other for seeing in the distance. These lenses are commonly used for patients over age 40 who can no longer see clearly at all distances with the same lens power. Bifocal or progressive addition lenses provide the convenience of not having to carry around two pairs of glasses.
For children, bifocals are more than a matter of convenience. They are often needed to provide optimum vision. When we look at near distances, we are required to use more focusing effort than is used for seeing at far distances. While most children have a sufficient amount of focusing ability, they sometimes use it inefficiently. During school, children can spend up to 75% of their day focusing on near tasks. Some of these tasks require a child to make large rapid changes in focus, for example, when looking from the desk to the chalkboard and back again. If there is a deficiency in their focusing ability, it may cause blurring, discomfort and slower copying skills.Bifocal lenses help to make it easier on the eyes to focus by providing the lens power needed to see comfortably both up close and in the distance.
Other conditions for which bifocals may be prescribed for children include binocular vision disorders and visual problems associated with desk or computer work. Excessive close work may also be related to an increase in nearsightedness. A bifocal prescription may help to limit the onset or progression of nearsightedness.
Bifocal lenses may be used continuously or for a limited period of time and when they have served their purpose they may no longer be needed. Wearing a bifocal prescription will not create a dependency for these lenses.
Children adjust to wearing bifocals quite easily. They can also be obtained in a "no-line" form to eliminate the appearance of lined lenses, but some children cannot use these lenses effectively or the appropriate lens power may not be available in that type of lens. Your doctor will specify what type of bifocal will be best for your child.
An optometrist who is a member of COVD can provide a thorough examination to determine if bifocal lenses will benefit your child. Fellows of the College of Optometrists in Vision Development (FCOVD) are board certified in developmental vision and in the diagnosis and management of children’s vision problems. For further information, contact COVD or consult with an optometrist who is a COVD member.
This informational paper was produced by the College of Optometrists in Vision Development, which board certifies qualified optometric physicians in vision therapy. For further information, see our website, www.covd.org. WP8 Rev 1/2/08 ©2008