Trifocal vs. Bifocal
Hello all, I am a contact lens tech, so I decided to come here for some spec advice.
My Mom has had numerous problems with progressive lenses. After switching materials, and numerous other attempts from the optician she is working with, she has decided to go to bifocals or trifocals. So her question is, when switching from a progressive lens, which would be the best for her to switch to, bifocal or trifocal? Could you give me the pro's and con's of each? I would like give her as much info as possible. Thanks!
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Your Mom probably needs a trifocal. If she gets only a bifocal, she will lose the intermediate zone and not be able to see at an arms length distance. A bifocal has focal points which are very near and far away. A trifocal has those plus an extra segment for the "arms length" distance. (which would be for a computer and such) Visit a reputable Optician and they can, based on her prescription, explain things a bit further. Without all the specifics, it's hard to say exactly what she needs.
Sometimes an independent opinion on the fit of the original glasses can reveal a fitting issue that the original optician or fitter may be reluctant to admit. We see several written rx's leave our office for purchases elswhere only to reappear with problems. The optician/fitter says there is nothing wrong with the glasses it must be the Drs. RX so the come back to us wanting to see the Dr. again after carefull examination of the eyewear we find either height or horizontal allignment issues. Your mother may want to take the glasses somewhere else to have them checked as the previous post mentions a reputable OPTICIAN there are to many people out there fitting progressives that dont have a clue of proper procedures. Just my two cents good luck
If your mom's add is +2.00 or stronger then she probably won't be able to see arms length well with a bifocal. This doesn't mean she will need a trifocal, lots of people do just fine without this distance being corrected well.
Trifocals often work better at computers then bifocals, but if the computer screen is straight ahead then even with a trifocal she will need to raise her chin and might find a separate pair of glasses works best for this.
I will often put the near prescription in a trial frame so the patient can look through it in the real world. Often near only without intermediate does just fine. Lots of people find the double lines and double image jump annoying. Plus there is less distance area in a trifocal.
However, I have fit lots of trifocals over the years and if correction at this distance is needed most people do fine with trifocals.
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Make it simple and let your mother.......................
When switching from a pal to a lined bifocal it will be another getting used to period. By getting a trifocal you are doubling the getting used effect and maybe confusion about it.
Originally Posted by KMK
Make it simple and let your mother get used to a regular bifocal with a larger than regular near segment, at least 28mm. A bit later down the road she will have an easy time to get adjusted to a trifocal if really needed.
It is also a less expensive solution.
My Mom's RX is +1.00 +1.25 X180 +2.25 add OD
+1.00 +.75 X175 +2.25 add OS
My Mom was able to successfully wear Progressives before after switching materials to the "Spectralite" material The problems that she encountered with other progressive lenses was object distortion. i.e. circles would look like ovals etc... It seemed that the Spectralite design/material helped. But then, with this newest pair of specs, the object distortion has resurfaced. These are also made in Spectralite, although from what I understand, they have changed their material slightly? (I know contacts but not eyeglasses sorry!)
So after several remakes, she is discouraged, and would like to try bifocals or trifocals. Thinking this may make things easier. We are in Michigan, don't know if someone here could take a look? Or any suggestions would be appreciated. Has anyone had a client with this object distortion before?
What progressive is she wearing? What was she wearing before? Spectralite has not changed to my knowledge. Are you sure she is in Spectralite which is an aspheric 1.54 index? There are only a couple of progressives that come in Spectralite.
Originally Posted by KMK
Last edited by Happylady; 05-31-2006 at 12:28 PM.
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You have to understand that unless it's the same frame, rx, lens, and measurements the glasses will be different no matter what. They haven't changed the Spectralite material, actually they're fasing it out from what I hear. So, it's probably a combination of things going on. Take the glasses back and voice your concerns and the problems she's having. There's a reason why this is happening and your Optician will be able to find out.
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