Bifocal Contact Lenses
Many patients travel to Sullivan – Ostoich Eye Center to be successfully fit with bifocal contact lenses.Dr. Ostoich and Dr. Klesken have had thousands of successful bifocal contact lens fits. Multifocal contact lenses are known to be difficult to fit. Several patients tell us they have tried other eye care professionals, but have not been happy with their contact lenses. Once they came to see Dr. Ostoich or Dr. Klesken, they could not believe how wonderful bifocal contact lenses could be. Patients can be fit with soft, disposable multifocal lenses, or with gas permeable contact lenses. Call today to schedule an appointment and our doctors can determine which type would work best for you! 847-776-8900.
Rigid Gas Permeable Bifocal Contact Lenses
Patients have two choices when deciding what type of RGP bifocal they would like. The first type of bifocal is a no line multi-focal and the second is a segmented (or lined) bifocal. We will go over the advantages/disadvantages of both.
NO LINE MULTI-FOCAL
- The most common no line multi-focal that we fit in our practice is the Essential bifocal. This lens has a “bulls-eye” in the center of the lens which will correct the distance vision. From the “bulls-eye” to the peripheral part of the lens the back surface gradually flattens to build in the bifocal component. The degree of flattening increases as the series of bifocal increases (series 1 to 3). Advantages: The Essential bifocal is a no-line multi-focal which means it gives the patient distance, intermediate and near vision. Advantages of this lens is it has 3 series of bifocals which increase in bifocal powers (most no-line bifocals only come in one bifocal power). The lens is not weighted since the bifocal goes completely around the perimeter of the lens so rotation of the lens is not important. By not having to weight the lens it is the same thickness as a distance only rigid gas permeable lens. Distance and intermediate vision is normally very good while the near vision is ideal for newspaper and magazine type print. Disadvantages: This lens may not be adequate for very small print (as you may see on the back of a medicine bottle). Some patients may feel that a low power pair of reading glasses are needed to see the very small print. Also, since the bifocal of a no line multi-focal is always on the back surface of the lens there may be some spectacle blur after removing the lenses after a days wear. The flattening of the lens curvature can also temporarily flatten the cornea (front surface of the eye) resulting in making the eye less nearsighted. In effect, the glasses will be temporarily too strong. Within a few hours the corneas will go back to their original curvature and glasses will again be clear. This will only be an issue if the patient wants to insert the lenses in the morning and wants to remove them when getting home from work (5 or 6 o’clock). There may be a couple hours where vision through glasses will be slightly fuzzy.
- The most common segmented bifocal we fit in our practice is the Tangent Streak by Fused Contacts. This lens contains the bifocal on the front surface where there is a visible (although very difficult to see) line going across the lens separating the distance (top) and the near (bottom). Because this lens has a “top” and “bottom” the lens must be weighted (or prism ballast). This results in a slightly thicker lens on the bottom half. In order for the lens to fit properly, the lens must rest on the lower lid, not rotate and show minimal vertical movement. The weighting of the lens will control all of those fitting aspects.
Advantages: This lens gives very good distance vision (very similar to the no line multi-focal). Near vision is extremely good. With this lens small print (as on the medicine bottle) is excellent. With this lens distance and near vision can be ordered to exacting specifications. Where as the patient with a no-line multi-focal can only go to series 3 (that is the limit to the bifocal strength), the segmented bifocal has no limitations. Therefore, the patient will never “out grow” this lens from a strength standpoint. There is no spectacle blur with lens since the bifocal is on the front surface (as opposed to the back as in the no-line). A patient can go back and forth between glasses and their bifocals and experience no spectacle blur.
Disadvantages: The lens is slightly thicker due to the weighting of the lens therefore wearing time in some cases is slightly less. The lens does not have intermediate vision. It only has distance and near.
This lens does come in a trifocal design. It is generally used with patients who have already adapted to the segmented bifocal (one line). After adapting to one line, getting used to the second line does not seem to be a problem. However, going right to a trifocal (2 lines) in some cases can be difficult adapting to.