Question on patient's reading glasses VD/prism--Help!?

[suzicoleman]

So I can't figure out what to do here. This patient ordered two pair of glasses, the distance glasses work fine, see the rx:
Distance:
Right -1.00 +0.50 155 1BU
Left -1.25 +0.50 025 1BD

The patient has problems reading through the reading glasses, and I thought at first it was just vertex distance, as they wear them down their nose. After calculating this, I realized that the power difference is definitely not enough to warrant a remake. So does anyone have suggestions about maybe the prism making them dizzy at the 18.5 vertex distance? I've never seen this happen prior to this patient. The patient is complaining that they get dizzy and can't read well at that vd. Patient was prescribed BI only at near. Help?

Near:
Right +2.00 +0.50 155 1BU 3.0BI
Left +1.75 +0.50 025 1BD 3.0BI

[Uncle Fester]

The answer lies in her old glasses.

What were their powers?

FWIW- I'd have called the examining doctor before I filled this rx as it is unusual.

Have them close or cover one eye. Is reading ok? Then do the other eye. If it's only when using both eyes it's probably the base in prism, however, a +3.00 add is going to create a short near focal length regardless. The vertical prism does not lend itself to their preferred position of wear.

I still want to know the old pairs power.

[Quince]

That seems like a large jump in prism for switching from DVO to NVO. Has the doctor confirmed the strength? My first guess is that it is a typo.

[suzicoleman]

The answer lies in her old glasses.

<<What were their powers?>> She didn't come in with any glasses, hadn't worn in more than a year.

<<FWIW- I'd have called the examining doctor before I filled this rx as it is unusual.>> We worked with this doctor at the time. This was written correctly.

<<Have them close or cover one eye. Is reading ok? Then do the other eye. If it's only when using both eyes it's probably the base in prism, however, a +3.00 add is going to create a short near focal length regardless. The vertical prism does not lend itself to their preferred position of wear. >> This is a great idea. Thanks!

<< I still want to know the old pairs power.

>> Sorry, no old glasses to check.

[suzicoleman]

<<

That seems like a large jump in prism for switching from DVO to NVO. Has the doctor confirmed the strength? My first guess is that it is a typo.

>> Yes, it is correct. He is actually very good with prescribing prism. Some patients only need at near. She's seen our ophthalmologist, and he found no difference in the prism.

[Uncle Fester]

[She didn't come in with any glasses, hadn't worn in more than a year.]

I'd expect her complaint as she's being whacked with a lot of new power.

You may need to walk her up to this full correction.

[Robert Martellaro]

>> Sorry, no old glasses to check.

A mature presbyope previously wearing OTC readers? Are the new SVNO eyeglasses less comfortable than the OTCs?

Verify that the horizontal prism direction is prescribed and fabricated correctly. Instruct the wearer to move the glasses closer, and to hold the object at a distance that provides the best and most comfortable vision, likely much closer than with the old near vision eyeglasses.

Hope this helps,

Robert Martellaro

[drk]

A +3.00 add with 6^ on the end of a nose?

That's the problem.

Cut that stuff way back, or push up the glasses a lot more.

[lensmanmd]

A +3.00 add with 6^ on the end of a nose?

That's the problem.

Cut that stuff way back, or push up the glasses a lot more.

+1. I'm with Doc on this one.

After calculating this, I realized that the power difference is definitely not enough to warrant a remake

Correct that the RX is not greatly affected, but the additional vd will add unwanted magnification even at that power. I would cut the RX back by 0.25 and cut the prism in half, if your patient insists on nose readers.

[suzicoleman]

See below. I actually tried this, spent a lot of time with this patient, and none of the above worked. I was pulling my hair out when I had the brilliant thought just to add pantoscopic tilt (a lot) to the frame, and voila! she was satisfied. I have no idea why it worked exactly, but she was fine with it, so no remake. Yay! She didn't like the reduced power, or reduced prism, or both. Thank you all for your input, it's so nice to know you guys have my back! :)

+1. I'm with Doc on this one.



Correct that the RX is not greatly affected, but the additional vd will add unwanted magnification even at that power. I would cut the RX back by 0.25 and cut the prism in half, if your patient insists on nose readers.

[drk]

Adding panto will add more minus cylinder axis 180 to interact with the mild oblique astigmatism correction (in some difficult to calculate way...).