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What is Presbyopia?
Presbyopic people have a reduced focus-adjusting ability, their lens loses its flexibility, making it difficult to focus on close objects.
During the early and middle years of life, the crystalline lens of the eye has the ability to focus both near and distant images by getting
thicker for near objects and thinner for distant objects. When this ability is lost, presbyopia results.
Years ago, people with presbyopia had only one option - to wear bifocals. Not today! We have several options that may meet your
needs. Dr. Kirshner will describe your options and recommend the best one for you.
Bifocal Contacts
Bifocal lenses come in two types, translating and concentric design. Translating bifocals work a lot like bifocal eyeglasses. They have
two power segments, with an obvious line of separation between the distance correction on top and the near correction below. Your pupil looks
through either one or the other, depending on whether you're looking far or near. This mechanism works in bifocal contacts because the lenses
stay in place even as your eye moves. Most bifocal lenses are gas-permeable (GP) rigid lenses.
Concentric ring-design bifocal contact lenses feature a prescription in the center and one or more rings of power surrounding it. If there are
multiple rings, they alternate between the near and distance prescription. Typically, at least two rings are within your pupil area, but this
varies as your pupil expands and contracts due to varying light. Concentric ring bifocal contact lenses can be made of either soft or rigid (GP) material.
Aspheric Multifocal Contacts
Aspheric multifocal contact lenses are similar to progressive eyeglass lenses, where the different prescriptive powers are blended across
the lens. Unlike eyeglasses, however, aspheric contact lenses are simultaneous vision lenses, so your visual system must learn to select the
proper prescription for the moment.
This is the only type of multifocal contact lens that can be described as "progressive." It's also concentric, like the concentric ring
design, and it has become the most popular type of multifocal contact lens.
Monovision
If bifocal or multifocal lenses do not work for you, another alternative is monovision. With monovision, you wear one contact lens with one
power to correct distance vision and the other contact lens with one power to correct near vision. The distance vision lens is usually worn
in your dominant eye.
While monovision may appear to be an unusual choice, most people actually accommodate well to it, and eventually don't even notice that
each eye is responsible for a different part of their vision. Because each lens has only one power, your doctor can prescribe any of the
currently available spherical lenses for monovision, including all of the current disposable lens options.
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