Multifocal Contacts Types and Designs
Types and Designs Of Multi Focal Contact Lenses
If you have presbyopia wearing multifocal contacts are one of the best options for correcting your vision. But how much is the vision improvement you can expect from the lenses?
An experienced eye doctor usually communicates about what you can expect from multifocal lenses during your contact lens fitting. He or she might say that your lens fitting is good, if you can perform about 80 percent of your daily activities well. For example, your occupation requires you to see objects between reading distance and far distance. They are considered a good fit if you can read phone book and, at the same time, working on the computer comfortably.
The following lens designs offer you possibilities. Find out each strengths
and weaknesses so that you know what to expect from
multifocal lenses available in
the market.
Multifocal Contact Lens Types
Based on how the power distributed, there are three different multifocal contact lens types: concentric, aspheric and translating designs. Concentric and aspheric designs are often grouped into a simultaneous design because in both designs the lens power is distributed gradually.
- Concentric design. The
design of concentric multifocal contact lens is more complex than the concentric
bifocal contact lens design.
The bifocal lens design only utilizes concentric zones or rings for far and near focal points.
But the multifocal design adds an intermediate vision correction in the
outer ring.
Similar to bifocal lens design, the near correction is in a small circle at the center of the lens, while the distance correction is at the outer, much larger circle. Or, the distance correction is in the center, surrounded by the outer circle as the near correction.
But in a multifocal design, when the center circle correct distance vision, the outer ring can contain a progressive that provides a smooth vision transition from distance to near vision, or vice versa. This offers crisp vision in intermediate distance between 18 to 34 inches -- a distance between the eye and a computer. - Aspheric design. In the aspheric design, the near and distance corrections are
within the pupil area. The lens produces a varying power continuously from the
near correction center radially toward the distance correction edge.
With this simultaneous design, your eyes adjust power to see an object depending on how close or far its position is. - Translating or alternating design. One translating design mimic "half-moon" segment of bifocal spectacle lenses. The half moon segment corrects near distance and the rest of the lens corrects distance vision. To maintain the near correction at the bottom, the multifocal lens is weighted with extra thickness.
In another translating design, the bottom part of contact lens is slicing off to make it flat. With the truncation, the lens keeps from rotating on your eye as you blink. In this design the near prescription is on the bottom. So, when you read a book, your eyes move downward to see through the lower portion of the lens. And you'll see distance by looking over the upper part.
Which Multifocal Contacts Design Is Right for You?
Each multi focal design is suited to certain anatomical issues and vision correction needs. Sometimes one eye "fits" into one particular design or material, but the other eye may need a different design.
Multifocal lenses will not solve all of your vision needs. But the key here is the lenses should answer your main activities' vision needs. If you're looking for a perfect fit you may end up becoming a never satisfied patient.
So seek more info about bifocal or multifocal contacts to help you find one design that works for you. And then visit your eye doctor for a contact lens fitting.
Back from Multifocal Contacts to Presbyopia Contact Lenses Home
| More Information |
|
|
| Copyright © 2006-2008 Presbyopia-Contacts.com. All Rights Reserved. |
