Traditional Presbyopia Correction
Presbyopia (pronounced prez-bee-OH-pee-uh) is a condition in which the crystalline lens of the eye does not easily adjust to focus on objects at varying distances. This condition is also known as “loss of accommodation” because the eye loses its ability to accommodate, or move to focus. Presbyopia (which literally means “aging vision”) affects most people sometime after about age 40, making it difficult to focus on close objects or read small print.
Theories about the cause of presbyopia vary. Presently, most vision experts believe the condition is due to loss of elasticity of the eye’s lens, continued growth of the lens, or weakening of the muscles controlling the lens—or possibly a combination of these causes. Other theories exist as well.
Traditionally, people with presbyopia have used corrective eyewear—reading glasses, bifocals, or progressive lenses—to see things clearly at a close distance. Reading glasses (used only for reading and close work) simply magnify whatever the person is looking at. Both bifocals and progressive lenses include two prescriptions, typically one prescription to improve near vision and the other to improve distance vision. In bifocals the prescriptions are separate; in progressive lenses, one prescription gradually leads into the other.
Three types of contact lenses also are used to temporarily correct presbyopia: bifocal contact lenses, multifocal contact lenses, and monovision contact lenses. Bifocal lenses work very much like bifocal glasses. Multifocal lenses (of which numerous variations are available) provide multiple points of focus for a natural transition from very close to far distance vision. Monovision lenses work on a different principle from bifocal and multifocal lenses. Monovision uses the patient’s dominant eye for distance vision and the non-dominant eye for near vision. (Typically right-handed people are right-eye dominant and left-handed people are left-eye dominant, but it’s best for an eye doctor to make this determination.) While there is always an adjustment period for patients new to monovision lenses, usually the brain becomes accustomed to processing the two different images in an appropriate manner.
While LASIK procedures have greatly helped many people with vision problems such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism (curvature of the cornea), conventional LASIK will not correct presbyopia. In fact, patients who have successful LASIK surgery may develop presbyopia later in life. Conventional LASIK neither protects against nor predisposes the patient to presbyopia.
The good news is that surgical options for correcting presbyopia do exist. Current alternatives include LASIK Monovision and Conductive Keratoplasty (both of which adjust one eye for near vision and the other eye for distance vision), Surgical Reversal of Presbyopia with Scleral Expansion Bands, Anterior Ciliary Sclerotomy, Laser Presbyopia Reversal, and lens replacement options such as the crystalens™, the ReSTOR ® Intraocular Lens and ReZoom™ Multifocal Intraocular Lens.
Whichever procedure you choose, it is important to have a good LASIK surgeon such as those at the Clear Advantage Vision Correction Center in Portsmouth, New Hampshire.
