Hello. I have a customer who is a Ukrainian refugee. She had her computer glasses made there. Now she is here. No Rx, no glasses, no car, nothing. She has pictures of lens packaging of her old glasses. It is Hoya AddPower. I am unfamiliar with this lens. The lens envelope marked SHV70 +300 AP150. The question I have: Is it +150 for the computer and +300 reading or +3.00 for the computer with +4.50 reading?
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"Hoya AddPower Trueform 60 & 120Freeform Aspherical enhanced reading lens made in CR39 material. A degressive design: the lens power degresses 0.75D or1.50D from the full reading Rx which is 8mm below the fitting point. It is recommended to have a minimum of 16mm from the fittingcross to the top rim. Suitable for visual tasks up to 60cm.Fitting Determine the mono-NCD measurements. Order the near prescription powers. The fitting point should be glazed on thehorizontal centre line approximately 3mm below pupil centre. It is recommended to fit the frame prior to taking the measurements.Not suitable for driving. Prism available. Orders must specify whether they require Trueform 60 or 120" -
Originally posted by NAICITPO View Post
Thank you for your prompt responce. So...where does it leave me in terms of her Rx? +3.00n reading digressing to +1.50 on top?Comment
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So a degressive lens = NVF
So I assume the top of the lens was +3.00 and the bottom was +4.50. When ordering a near variable focus lens you put in the full rx and the lab software spits out the power depending on how far of a focal point you want that's somehere between 40-60% of the total power at near.
Have you guys refracted her?Comment
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We haven't refracted her and she does not have her glasses or her written Rx - otherwise I would not have questions. I know what a degressive lens is. My question was: does anybody know what was her glasses with that kind of marking on the lens envelope?Comment
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Sorry I didn't understand the question. If it were me I would trial +3.00 at arms length and +4.50 for near.Originally posted by mish View PostComment
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So would I, but.... she is not even near.:( She is a friend from Ukraine living now (for the last few months) in Toronto. They gave her an eye exam and made her glasses there she is very unhappy with. I have her Canadian written prescription and her Canadian SV glasses she cannot tolerate for more then 10 minutes and pictures of the lens envelopes they did for her in Kiev that she likes. I am trying to solve the puzzle - is it the new Rx, is it the PD they messed up in Toronto, is it the lens design, etc. Kind of like what I had to go through during covid times when people where hiding in the countryside and sending me their 20 years old pictures so I would try to figure out their PD, seg height, frame size and such:)
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...and what she sent me are her new SV computer glasses so it is even more challenging to sort things out:(Comment
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We used to have Add Power here years ago, this is what I recall of those lenses as we got them locally here in Malaysia...
The stated Rx on the envelope was the near reading Rx, and the type of design (0.75 or 1.50) was the degression.
However, the full degression was hardly achieved except in extreme up-gaze, so Add Power 0.75 wearers usually only benefited from about a maximum 0.50 degression.
We never had Add Power 1.50 here.
Other than that, SHV was the name of what used to be the usual Hoya AR here (Super Hi-Vision), and the 70 referred to the uncut diameter.
Add Power lenses could not be decentered as I recall, had no inset, and so were fit similar to a bifocal (with the top of the reading circle treated as the top of the segment).Comment
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Thank you:)Comment
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