MULTIFOCAL CONTACT LENSES
Multifocal contact lenses are designed to provide clear vision at all distances for people experiencing a decline in near vision called presbyopia.
Presbyopia is an age related condition that usually becomes noticeable in our 40s or 50s. Presbyopia affects our accommodation in our eyes, which causes us to not see clearly when reading menus, newspapers, books, smart phones, tablets and other reading materials.
Multifocal contact lenses come in both soft and hard (rigid gas permeable, GP) materials. They are also available as hybrid contact lenses, a combination of a hard and soft contact lens. Some can be worn on a disposable bases, which means you can wear them for a specific time (i.e. two weeks or a month) or even every day. You should always replace your contact lenses with a fresh and new lens to ensure optimal eye health. Ask your eye care professional how to wear and take care of your contact lenses.
How Multifocal Contact Lenses Work
Multifocal contact lenses work in several different ways, depending on the design of the lens. There are two main designs of a multifocal contact lens:
- “Alternating vision” (translating) lenses allow your pupil to alternate between the two powers, as your gaze shifts upward and downward.
- “Simultaneous vision” lenses require your to be looking through both distance and near powers at the same time. With this design, your eyes are able to select the correct power choice within the lens depending on how close or far you’re trying to see. All multifocal lenses take time to adapt to.Simultaneous vision lenses come in two types: concentric ring designs and aspheric designs.
Concentric designs have the distance prescription in the center and is surrounded by rings of near and far power. Near-center versions are also available.Aspheric designs have the near and distance prescriptions in front of the pupil.
Translating design have the near power on the bottom and distance on the top. The bottom edge is flattened to keep the lens from rotating on your eye when you blink.
Concentric Ring Designs:
This design features 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 within your pupil area, but this varies as your pupil expands and contracts due to varying light.
Aspheric Designs:
These multifocal contact lens designs work more like progressive eyeglass lenses, where the different prescriptive powers are blended across the lens. Your visual system must learn to select the proper prescription for the moment because these contact lenses have simultaneous vision. Aspheric designs are most popular and best described as “progressive”.
Are Multifocal Contact Lenses Good for Me?
Multifocal contact lenses gives you the convenience of not having to wear progressive eyeglasses and see comfortably at all distances. New technology has produced more successful and advanced designs. Your Optometrist or eye care professional will determine which design is best for you and have you try on different multifocal contact lenses to ensure you achieve the most optimal vision.
Your eye care professional will consider your pupil size and near prescription to determine which multifocal contact lens is right for you. Your vision can be complicated and depending on your prescription, your eye care professional will conduct techniques such as monovision to achieve the best possible vision.
Visit us to see if your a good candidate for multifocal contact lenses. We will do a comprehensive contact lens fitting and provide free trial lenses to make sure your visual needs are addressed and identify the best multifocal contact lens for you.
Source: http://www.allaboutvision.com/contacts/bifocals.htm#work