bifocal contact lens wear


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Bifocal Contact Lenses for Near and Far sight (Presbyopia)
As with bifocal glasses, bifocal (and multi-focal) contact lenses are used to treat patients with problems of both near sightedness and far sightedness, a condition known as presbyopia. Bifocal contact lenses can be difficult to fit, and may require several lens changes before the right one is found. However, many patients find them worth the trouble.

Bifocal contact lenses are available as daily disposable, frequent replacement, multi-package disposable, rigid gas permeable, soft, and even toric (to treat astigmatism) contact lenses. There are two basic designs for bifocal contact lenses and within those designs are varieties of Rigid Gas Permeable and soft contact lenses.

DESIGNS

1. Simultaneous
  • Designed to allow the patient to see both near and far at the same time. Requires patient to choose which image to focus on.
  • Near and far refractions are superimposed.
  • Lenses do not use a prism.
  • Uses an aspheric design.

2. Alternating

  • Have small optic zone diameters. The patient alternates between zones as necessary.
  • Use a prism to stop lens rotation.

RIGID GAS PERMEABLE BIFOCAL CONTACT LENSES

  • Have steep vision
  • Corneal apex, lower lid position and pupil size along with lens performance, must be considered when fitting the lens
  • Simultaneous RGP
    • Allow patient to see near and far simultaneously, requiring patient to choose which image to focus on
    • Easier to fit than alternating
  • Alternating RGP
    • Near, intermediate, and distant powers are arranged in concentric rings
    • Pupil size dictates zone size

SOFT BIFOCAL CONTACT LENSES

  • Most preferred type in soft bifocal contact lenses
  • Allows patient to see near and far images simultaneously, requiring patient to choose which image to focus on
  • Anterior Aspheric Surface
    • Ideal for patients who require better vision in bright light
    • Posterior Aspheric Surface
    • Ideal for patients who require better near vision in bright light
  • Alternating Soft Contact Lenses
    • Can be near centered or far centered
    • Pupil size important in near centered lenses

Speak to your doctor at your next exam. One of these choices may be right for you.

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