As you get older, there is an increased possibility that you will develop a condition called presbyopia. Presbyopia is defined as the loss of “near focusing ability,” and it’s very common for people after the age of 40. This means that you could have trouble reading books, or text messages on your cell phone, even the details on a gift card or store receipt.
Presbyopia is on the rise in the United States, according to the U.S. Census Bureau. The number of Americans who suffer from the condition is expected to rise from 112 million in 2006 to 123 million by the year 2020.
In the past, most Americans would be forced to use a pair of bifocal glasses, or a pair of specialized reading glasses, to handle the symptoms of their presbyopia, but today many eye care manufacturers are making various kinds of contact lenses that are designed to allow the wearer to have the close-up focus they need without wearing bifocals or having the hassle of taking a pair of readers everywhere they go.
Multifocal contact lenses come in a variety of forms. We discussed many of those options in a previous blog entry regarding the different types of contact lenses. Rigid gas-permeable lenses and soft lenses designed for daily and overnight wear are available, as well as soft lenses that are designed to be worn on a part-time basis. One-day-wear disposable soft multifocal lenses that allow for the convenience of new lenses each day have recently become available.
Regardless of the format you choose for your multifocal contact lenses, they will come in one of two major designs. The first is called simultaneous vision designs. These lenses have different zones of the contact lens designed for near or far vision.
There are two options for simultaneous designs:
- Aspheric multifocal lenses. These lenses have a zone at the center of the lens that is designed to focus on near objects such as text, and then the focus of the lens slowly progresses toward the outer edge, to focus on distance viewing. This makes the lenses similar to progressive lenses for eyeglasses.
- Concentric multifocal lenses. These lenses have a primary viewing zone in the middle of the lens. Surrounding that center are concentric rings of near and distance zones. Unlike aspheric lenses, the center zone is usually focused on distance viewing. These lenses can also be used in some cases with a distance center focus in the lens that is in the user’s dominant eye, while the weaker eye has a near-viewing dominant focus.
The other major design for multifocal contact lenses is the segmented multifocal lens. The design of these lenses is very similar to bifocal eyeglass lenses. These lenses allow you to view closer items or text by looking down at them. Unlike other lenses, these kinds of multifocal lenses only come in rigid, gas-permeable lenses.
These lenses are also available as trifocal lenses.
If you are dealing with presbyopia and want to look into contact lenses as a form of treatment, then you need to meet with our contact lens expert here at EyeCare 20, 20, Dr Nicholas Xanthos. He can help to decide which lenses are right for you. Schedule an appointment with the staff of OCLI today to find out about your treatment options!