New York, NY (PRWEB) February 17, 2009
Beginning in the mid 40s, everyone with good distance vision starts to experience blurred vision at near points, such as when reading a book, newspaper, putting on eye make-up or even working at the computer. This happens to everyone with good distance vision, even if they never used glasses before, states Kevin Niksarli, MD of Manhattan Lasik Center.
Kevin Niksarli, MD estimates that approximately 100 million people in the United States either have presbyopia, or will develop it by 2016. This is generating a huge demand for eyewear, contact lenses, and surgery that can help presbyopes deal with their failing near vision.
When people develop presbyopia, they find they need to hold books, magazines, newspapers, menus and other reading materials further and further away in order to focus properly. When they perform near work, they may have headaches, eyestrain or feel fatigued.
Presbyopia is caused by an age-related process. It is different from astigmatism, nearsightedness and farsightedness, which are related to the shape of the eyeball and caused by genetic factors. Presbyopia is generally believed to result from a gradual loss of flexibility in the natural lens inside our eyes.
These age-related changes occur within the lens, making it harder and less elastic over the years. Age-related changes also take place in the muscle fibers surrounding the lens. With less elasticity, the eye has a more difficult time focusing up close.
Eyeglasses with bifocal or progressive lenses are the most common correction for presbyopia, adds Kevin Niksarli, MD of Manhattan Lasik Center. Bifocals involve two points of focus: the main part of the spectacle lens contains a prescription for distance vision, while the lower portion of the lens holds the prescription for close work.
Progressive addition lenses are similar in principle to bifocal lenses, but they offer a more gradual visual transition between the two prescriptions, with no visible lines between them.
Reading glasses are another commonly used option. Unlike bifocals and progressives, which people need to wear all day, reading glasses are typically worn by those with good distance vision, only during close work. If you wear contact lenses, your eye doctor can prescribe reading glasses that you wear while your contacts are in. You may purchase readers over-the-counter at a retail store, or you can get higher-quality versions prescribed by your eyecare practitioner, filled at the optical store.
There are also contact lenses available for presbyopia, called multifocal contact lenses. You can obtain multifocal contact lenses in different lens materials. Another type of contact lens correction for presbyopia is monovision, in which one eye wears a distance prescription, and the other wears a prescription for near vision. The brain learns to favor one eye or the other for different tasks at appropriate distances. About 50% of the people trying it are delighted with this solution, while the other half misses the binocular distance vision.
Because the human lens continues to change as we grow older, our presbyopic prescription will increase over time as well. New surgical options to treat presbyopia are being researched and are already available in many countries, adds Kevin Niksarli, MD. One example is NearVision CK treatment, which uses radio waves to create steeper curvature in the cornea to improve near vision. However, the most common surgical method to induce monovision remains LASIK, most often used for people who need to have their distance vision corrected anyway, and opt for the monovision method. Less commonly it is used to induce near vision in just one eye for someone with already good distance vision.
Up until recently, patients undergoing CustomVue LASIK were not able to have the monovision option. The recent FDA approval of iLASIK procedure for monovision now allows surgeons to more accurately correct the distance as well as the near vision of presbyopes, states Kevin Niksarli, MD of Manhattan Lasik Center. This has made LASIK, an already great and popular procedure, even more versatile for those with presbyopia.
With the recent introduction of presbyopia-correcting multifocal or accommodating intraocular lenses, some people undergoing cataract surgery may also be able to achieve clear vision at all distances. However, even though the cataract surgery is fully covered by health insurance, these optional add-on lenses become out-of-pocket expenses for the patients.
Kevin Niksarli, MD of Manhattan Lasik Center recommends discussing the various forms of presbyopia correction with your eye care practitioner in detail, and choosing the one that fits your clinical picture, vocational and recreational needs.
Ralph Perez, director of public relations
Manhattan Lasik Center