Advice on markings on progressive lenses

[eyemaniac]

Hi everyone, I manage a small optical surfacing lab for a company with three retail stores. My question is concerning how to fit a progressive in a particular frame using the markings on the lenses. I am not an optician and my expertise is not in fitting lenses in frames, although I do understand the whole principle. Do most of you try to get distance circle marking and reading circle marking inside the frame for the best fit. I was taught that 100% of the reading was approx. in the center of the circle markings not at the bottom of the markings. Can anyone with more experience than me tell me their thoughts on fitting a lens into a frame using the markings on the lens. I know this question is drawn out but couldn't find the words to explain it differently. Sorry!

[braheem24]

Some manufactures have 100% of the add in the reading circle, others have 85% varies from one to another, getting both circles to fit in the frame would be good safe practice.

[Uncle Fester]

I'll second Braheem's advice. As a bench-person am I right in guessing that you get asked to put too many long corridor progressives into to narrow a B?

It's a sticky wicket for the fitter to balance the risk of switching to a short corridor when the patient chooses a frame too narrow to properly fit the previous lens design. Depending on the person and the lens I've run the gamut from adamantly telling them to choose another frame to switching them to a relatively radically different design to even on rare occasion asking the doc to up the add to compensate for the reading area being cut off.

Anyway I hope you don't get blamed when someone else fits lenses outside of suggested minimum fitting heights!

[eyemaniac]

Actually I get a lot of the opposite, short corridor into large B's and I think you do an injustice to the patient when you do that. We have people who will take for instance a small fit with a seg height of 19 and put it into a frame with a 40B. I see a lot of that and I do not think there using the correct lens. Any thoughts.

[EyeCare Rich]

Depends on the patient and Rx. Low add, reads alot, not a bad fit. They loose a little in the midrange, but may not affect lifestyle. I really believe it depends on the patient being fit.

[Robert Martellaro]

Hi everyone, I manage a small optical surfacing lab for a company with three retail stores. My question is concerning how to fit a progressive in a particular frame using the markings on the lenses. I am not an optician and my expertise is not in fitting lenses in frames, although I do understand the whole principle. Do most of you try to get distance circle marking and reading circle marking inside the frame for the best fit. I was taught that 100% of the reading was approx. in the center of the circle markings not at the bottom of the markings. Can anyone with more experience than me tell me their thoughts on fitting a lens into a frame using the markings on the lens. I know this question is drawn out but couldn't find the words to explain it differently. Sorry!

The open circles on the template are there to reduce the area of lens that the lensometer "sees", limiting it's ability to sample the power change and unwanted astigmatism, providing for an accurate reading. They do not necessarily indicate a "proper fit", which is dependent on the individual, lens design, Rx, etc.

[Uncle Fester]

Actually I get a lot of the opposite, short corridor into large B's and I think you do an injustice to the patient when you do that. We have people who will take for instance a small fit with a seg height of 19 and put it into a frame with a 40B. I see a lot of that and I do not think they're using the correct lens. Any thoughts.

If only there was a hard and fast rule that worked all the time how much simpler a conscientious dispensing opticians life would be!

[Robert_S]

A lot of the time, fitting short corridor progressives for patients is the best option for them, regardless of whether it is necessary because of the depth of the frame they have chosen. It is also a much safer choice for previous bifocal wearers, who are used to have their reading area just beneath their pupil.

Of course there are also occasions where a longer corridor can be a huge benefit, but I tend to find that these are less common.

[EyeCare Rich]

If only there was a hard and fast rule that worked all the time how much simpler a conscientious dispensing opticians life would be!

Amen to that Uncle Fester!!!!

[eyemaniac]

I wish there were a few more replys on this subject, it seems from this post most of you are alright with fitting a short corridor lens in a big frame with a large B. It seems to me that if you have a short corridor lens with 25mm from top of circle to bottom of circle and putting it in a frame with 5mm of space below and 5mm of space above that you are not giving the patient the best lens available for that frame. Like I said previously, I am not a dispensing optician but this just doesn't make sense to me. Thanks everyone for your responses, greatly appreciated.

[EyeCare Rich]

As stated before, it depends on the patient you have in front of you, and their lifestyle, Their Rx, and Their taste in frames(Frame size). No one quick answer to this question. I suppose it also greatly depends on your choice/selection of lenses in your office.

[shannon]

An early presbyope doesn't have the need for the intermediate as someone older does. It is often beneficial to them to have a short corridor lens, regardless of frame size since there is much less intermediate to have to navigate through to get to the reading. This is often more comfortable for the patient to go from distance and almost straight into reading, bypassing a longer corridor of unnecessary power.

[cocoisland58]

I agree there is no hard rule for fitting long or short corridor progressives. Depends on the wearer's requirements. I wear a short corridor in a deeper frame because it works for me. Due to a tiny dispensing table and a close and low sitting computer monitor I need to crank my head back all the time if I wear a long corridor. When I fit a progressive I ask a lot of questions and fit accordingly. Seems to work 99% of the time.

[pseudonym]

... to even on rare occasion asking the doc to up the add to compensate for the reading area being cut off.

Thanks for that clarification- so often I read that you guys "bump the ADD" and I wonder if you are asking the doc to change the Rx or if you are just doing it yourselves because you know what needs to be done.

[pseudonym]

OK, I know you are supposed to mark a hyperope 1mm higher but are they better off with a long corridor or a short if they use a computer 8 hours a day?

[Uncle Fester]

Thanks for that clarification- so often I read that you guys "bump the ADD" and I wonder if you are asking the doc to change the Rx or if you are just doing it yourselves because you know what needs to be done.

The OD's I work for routinely write 2 adds and give the optician the option to use a stonger add because the early progressives had such long corridors.

I'm trying to get them to write only one add for emerging presbyopes especially, since the new digital progressives compensate and the corridors are generally shorter but it's hard to teach old dogs new tricks (myself included). Once the stronger add is used however I tend to stay with that in future fits (but not always!).

[see post 7]

[Uncle Fester]

OK, I know you are supposed to mark a hyperope 1mm higher but are they better off with a long corridor or a short if they use a computer 8 hours a day?

I'd say I need about 20 or more questions to answer that!

That said, a dedicated pair for the computer be it sv bi's or computer progressives are best for that amount of time on one.

[Judy Canty]

Remember, the fitting height set by the manufacturer is the MINIMUM fitting height, not the MAXIMUM. The design you choose is, or should be, subjective and based on the patients needs and wants.

[pseudonym]

Remember, the fitting height set by the manufacturer is the MINIMUM fitting height, not the MAXIMUM. The design you choose is, or should be, subjective and based on the patients needs and wants.

But with today's 28-30mm B's, I really struggle with fittings with hyperopes. I'm tempted to fit them higher or use a short fit but it doesn't always work. They come back complaining of trouble using computer while in a short fit.

[uncut]

But with today's 28-30mm B's, I really struggle with fittings with hyperopes. I'm tempted to fit them higher or use a short fit but it doesn't always work. They come back complaining of trouble using computer while in a short fit.

This is an opportunity, pseudonym!

I bet they also complain about running a marathon in high heels, too.LOL. What is it with this obsession by people, and some dispensers, to insist that one lens type can do everything well. It is reality that a multifocal, or a progressive, or a no-line, or whatever you want to call the lens............................will be deficient in several respects when you try to cram all those powers into a small piece of real estate. I find all short corridor multifocals are, by design.............barely bifocal in power usefulness, and if you want your patients to truly love you.............dispense them with computer products...........there are many.

To the OP...............usually the lens position is paramount in creating comfort to the wearer, so vertical and horizontal placement within the frame is dependent on the fit, or subsequent placement of the frame on the human anatomy. The function of the device is dependent on the communication between the dispenser and the client. Occasional obtuse fits, and bizarre measurements may be the result of occupational or lifestyle requirements.