22D Base in prism this time

[Trevor D]

I have a another doozy here for you guys if you would be kind enough to chip in some ideas.

Rx is:

R +0.75 +2.00 x 115

L -0.50 -2.50 x 80 (yes + / - is correct!)

Prism: 22 Base in split between R & L

Are those thick special cast CR39 blanks still available? Any other ideas about how I should go about this? My boss doesn't like taking on these types of jobs but I don't like to turn people away!

Thanks in advance :cheers:

Trev

[chip anderson]

Don't forget to notch the lenses nasally so the nose pads can be used.

[HarryChiling]

I have a another doozy here for you guys if you would be kind enough to chip in some ideas.

Rx is:

R +0.75 +2.00 x 115

L -0.50 -2.50 x 80 (yes + / - is correct!)

Prism: 22 Base in split between R & L

Are those thick special cast CR39 blanks still available? Any other ideas about how I should go about this? My boss doesn't like taking on these types of jobs but I don't like to turn people away!

Thanks in advance :cheers:

Trev

Stick on prisms. Or a really small frame with a large bridge (think big decentration to cut as muhc of the base away). Good luck.

[Jacqui]

Extra thick blanks are available in the US from X-cel and Vision-ese, I don't know about your area, but maybe Essilor (ick!!) or Zeiss or China. I don't like the idea of stick-ons, there can be tooo many problems. When you edge the lenses, roll the edges (no polish) for safety and to clear the nose pads.

[chip anderson]

Stick on prisms are strictly for temporary use for the prescriber to evaluate the success or need for more or less prism. Once this is done then one grinds this into a "permanent" lens.
They are a whole lot thinner of course being fresnel design.

Also note: The steeper the posterior curve is, the harder it is to get stick-on prisms (fresnel pasters) to work.

Note: Fresnel design has been used for many, many years in light house lenses.

Chip

[HarryChiling]

Stick on prisms are strictly for temporary use for the prescriber to evaluate the success or need for more or less prism. Once this is done then one grinds this into a "permanent" lens.
They are a whole lot thinner of course being fresnel design.

Also note: The steeper the posterior curve is, the harder it is to get stick-on prisms (fresnel pasters) to work.

Note: Fresnel design has been used for many, many years in light house lenses.

Chip

I'd have to disagree with you there, there comes a certain point where grinding it in isn't really gonna work, that's when stick on's work well. Sure they are a nuisance and if they are applied a bit off especially in the higher diopters they can cause some error, but they are a tool to be used.

[Trevor D]

Thanks guys, I might try the fresnel first on some finished lenses to see if the patient can tolerate the prism before we make up these whoppers. :idea:

[chip anderson]

Harry, U ever tried to put a Fresnel paster on -10.00 or more concave surface? Even if you succeed I wouldn't expect it to last 3 days if the weather was good.

Geeze Harry, this is twice in one week we have seen things differently.


Chip

As usual I only half paid attention to the origional post, I thought he had -22.00 with an 11 diopter base in OU.

[EyeSing]

The low vision lab I used to work in would do an AWESOME job with these. I've seen them come out with some pretty incredible stuff. If you want more info, go to www.chadwickoptical.com Karen Keeney specializes in these types of lenses.

[bt5050]

was wondering - what does the pt have currently ? any prism >?

is this going to be a permeant thing - or is it just pre or post op ?

I would much rather wear the press on - then have to deal with ground in prism such as this -

have you spoke directly to the perscriber yet ?
with anything - such as this - I find it very benifical to contact them - and get understanding what the treatment is - and what the expectations where that where communicated to the pt -

also - i have found it makes it much better - that once you rec. the glasses back - and if there is any ?'s about them workign correctly for the pt -

the majority of the time - it is not needed to keep sending them back - to be remade - since the org rx - had a fairly large range - and the end result was just something in the area that was needed -

[HarryChiling]

Harry, U ever tried to put a Fresnel paster on -10.00 or more concave surface? Even if you succeed I wouldn't expect it to last 3 days if the weather was good.

Geeze Harry, this is twice in one week we have seen things differently.


Chip

As usual I only half paid attention to the origional post, I thought he had -22.00 with an 11 diopter base in OU.

LOL, no I wouldn't try on a curve like that, but you can put it on the front too.;) I wouldn't call it disagree with you especially since I like this kinda work, it might be difficult to find a lab to do something like this though.

[fvc2020]

I just wanted to chime in...


Did something just like this recently for a Graves patient. Trialed out the press on and then made her glasses. My lab rocked at it and they looked incredible.....Very doable...I use TCO in Minneapolis...Call and ask for Tripp and he can walk you through this(and your lab)..Tell them Christina at Family Vision Clinic gave them their number. They'll remember the patient

Their number is 763-551-2200


Christina

[Michael Walach]

Hi Trevor,

Your boss is right; why bother with jobs like this. You are right too -do not run your customers away! Send your pain in the neck jobs to QUEST OPTICAL SPECIALTY LAB, that is the kind of jobs we do all day long. This way you do not turn your customers away, you have time to concentrate on your daily jobs that you do well and still make your $! We do business with wholesale labs only. www.qoestopticallab.com

Michael

[gmanlook]

This job isn't really that bad. You need extra thick blanks (X-Cel) you can also get them with plano back which adds more to the thickness. I managed a specialty lab for 8 years and one of the hardest parts is to not create more prism than you want. When you are surfacing them they have a tendency to remove more stock from the thinnest edge. This is where the challenge is. I had to modify my cyl. machines to accomodate running these RX's. Try the fresnel to get in the ball park first! When you know what the total is, run it...and good luck. Gary

[harry a saake]

in order to get these lenses uniform you will probably have to do an uneven split, rather then 11 in each eye, as you have an apx + 225 going across the 180 in one eye and apx -2.25 in the other, this will work as long as they total to 22, i,m thinking in my head apx 15/7

[Judy Canty]

Personally, I'm hoping that after 4 months, the job is ready for pick-up. ;)

[DragonLensmanWV]

Harry, U ever tried to put a Fresnel paster on -10.00 or more concave surface? Even if you succeed I wouldn't expect it to last 3 days if the weather was good.

Geeze Harry, this is twice in one week we have seen things differently.


Chip

As usual I only half paid attention to the origional post, I thought he had -22.00 with an 11 diopter base in OU.

On a -10.00 I would put it on the front, a nice flat surface in that Rx.

[Trevor D]

Sorry guys for not posting an update after the specs were collected! Yes it's well and truly finished after 6 months but after using a fresnel stick-on on one lens (after consulting her doc), we have not heard back from the patient and probably won't until the thing falls off. It must look funny outside as the lenses are transitions....

Trev

[Uncle Fester]

Sorry guys for not posting an update after the specs were collected! Yes it's well and truly finished after 6 months but after using a fresnel stick-on on one lens (after consulting her doc), we have not heard back from the patient and probably won't until the thing falls off. It must look funny outside as the lenses are transitions....

Trev

A cyber Foster's says the stick on got peeled off and the patient is back to monovision.;)

What's with the +/- cly BTW? Sloppy comes to mind. Have you dealt with this doc before?

[specs2see]

i agree, fresnel prism's are a great diagnostic tool however, they are very temporary and the patient will have trouble keeping them on, even with shallow back curves. your best bet in my opinion is to get the blanks from vision ease or also i know specialty lens uses to be able to make anything you need. you may also want to contact VM products in livermore calif. i know the owner there has a bunch of older blanks lying around.
be careful with the frame selection try to use a frame that will allow good pad ajustment and as small of a frame as you can use.
also i know how you feel about never wanting to turn anyone away, but sometimes you have to.

[chip anderson]

How bout referring the patient to a good ophthamic surgeon specializing in adult strabismus.

Chip