• Call (215) 443-7706
  • Bifocal Glasses

  • Bifocals are Glasses with Two Focal Lengths

    Bifocals are glasses having lenses with two different focal lengths.  Bifocals are commonly prescribed to people with presbyopia who also require a correction for myopia, hyperopia, and/or astigmatism.  While most presbyopes these days choose line-free progressive lenses, conventional lined bifocals and trifocals have some advantages over progressives. In particular, bifocal and trifocal lenses usually provide wider lens areas for reading and computer work than progressive lenses.

     

  • If you can read something better while wearing your current glasses and holding the book or pill bottle at arm's length, you probably need bifocal glasses.

    Recurring headaches, neck strain and upper shoulder pain may indicate your eyes have changed and need a different prescription. Unconsciously squinting or holding your head a certain way for long periods will eventually cause muscle discomfort in your face, neck and shoulder areas.

    Bifocal glasses are for a person who need two separate prescriptions, one to see clearly at a distance and a different one to see up close. The person is both nearsighted and farsighted.  A small portion in the lower part of the bifocal lens contains the power required to correct your near vision. The rest of the lens usually is for your distance vision.

    The lens segment (or "seg") devoted to near-vision correction can be one of several shapes:

    • Half-moon — also called a flat-top, straight-top or D segment
    • Found segment
    • Narrow rectangular area, known as a ribbon segment
    • Full bottom half of a bifocal lens, called the Franklin, Executive or E style

    Bifocals have visible lines, but the line in round-segment bifocals tends to be less noticeable than the lines in flat-top and Executive styles.