transposing plus cylinder Rxs

[k12311997]

Do you transpose Rx written in plus cylinder before ordering? and why.

I always do, mostly just because that was what I was taught. You neutralize and check in jobs in minus so that is how you order them.

[chip anderson]

If you want to speak contact lens, you have to convert. I have known a few labs that charged $0.50 for converting spectacle Rx's to minus form but most lenses had cylinder on posterior surface at that time.

Chip

[optical24/7]

Do you transpose Rx written in plus cylinder before ordering? and why.

If it's stock lenses, most on-line ordering systems require it. I don't do it on Rx's though. Order as written, less chance of ordering error.

I always do, mostly just because that was what I was taught. You neutralize and check in jobs in minus so that is how you order them.

I don't transpose when neutralizing either. Neut. as written. Once again, less chance of error. (Why give yourself extra work?)

[Chris Ryser]

I don't transpose when neutralizing either. Neut. as written. Once again, less chance of error. (Why give yourself extra work?)

any old optician should be able to shake this out of his amrpit................

[Craig]

We enter the RX as written, but my software is set up to convert all orders to minus cyl. This means we are consistent and if you send in a lab order in plus cyl, there will be some mistakes.
There is no reason to not use minus cyl for all work in my opinion.

[k12311997]

I don't transpose when neutralizing either. Neut. as written. Once again, less chance of error. (Why give yourself extra work?)

by neutralizing I'm refering to determining the rx from lenses without a prescription to check against. as to why create more work? my answer is uniformity.

[k12311997]

any old optician should be able to shake this out of his amrpit................

????

[bhess25]

so then why do Md's and some OD's write in plus cyl? I get that some use plus cyl phoropters, but if this is something people think can cause errors why not make minus cyl universal?

[Wes]

Why do some people choose macs over pcs?

[Wes]

Why so some people choose nissan over honda?

[chip anderson]

Actually the plus and minus for the optical industry had to do with whether the cylinder was ground on the front or back.
The OD OMD difference had to do mostly with Jack Copeland who taught plus cylinder refraction to MD's and appearently didn't teach too many OD's.

Of course there was a time when Canadians made cars with postive ground, the US did negative ground.

Chip

[uncut]

Yes.....I make it a habit, only to reduce errors during lab orders, verification, etc by staff members, lab personnel. Personally, I am of a vintage where transposing was a 50/50 thing on a daily basis, since I worked/work in a mostly ophthalmic capacity. My lensometers transpose for me, if required, so no issue in that area.

I feel its a potato/potatoe or a tomato/tomatoe thing...............

[braheem24]

so then why do Md's and some OD's write in plus cyl? I get that some use plus cyl phoropters, but if this is something people think can cause errors why not make minus cyl universal?

+0.00-300 is easy in a -cyl phoroptor and a headache in +cyl to refract. (-3.00+3.00)
+3.00-3.00 is easy in +cyl phoroptor and a headache in -cyl to refract. (+0.00+3.00)

With -cyl you're constantly adding a -0.12 sph equivelant and adding plus to offset.
with +cyl you're constantly adding a +0.12 sph equivelant and adding minus to offset.

I neutralize according to written rx + or - but can only refract or make sense of an rx in -cyl

[optical24/7]

by neutralizing I'm refering to determining the rx from lenses without a prescription to check against. as to why create more work? my answer is uniformity.

k, the only time this happens is if I'm duplicating, then yes, I'll notate it in minus.

Chris, after 36 years in labs I've transposed more than a couple of Rx's.


If it's not nessesary, why do it? For practice? Most Rx's I get now a days are in plus. (referring OMD's.) I enter Rx work through a computer interface strait to the supplying surfacing lab. I don't see transposing errors from them. Being a labrat, I'm most used to working in minus, but plus is no big deal.

[For-Life]

No. Though, for Stock Club and Medical Services, they demand minus cyls. If it is plus, that is how I enter it into the computer and verify the order.

It is very simple to convert, but errors happen and this is one potential step where it can happen.

[optilady1]

Since working for an MD practice for the last year and a half, I've retrained myself to only think in plus. Every once in a while we get an outside rx in minus, and I write what's written. Of course that all goes out the window when I'm doing a cl fit, but it doesn't happen too often.

Back in the day, before the LC updated their lab software, we had to enter in everything in minus, and there was usually one mistake a week due to entering something in wrong.

[FVCCHRIS]

Never complicate things by "changing" it. I write up, order, and check in the Rx exactly as written. Plus Cyl, or Minus, whenever you make the decision to change it to something else you add a layer of complexity to what we do and also every change is a chance to screw things up. Keep it simple by leaving it alone.

[Now I See]

The only time I transpose is when I'm ordering stock lenses. Otherwise, I order and inspect the final work as written.

[Striderswife]

Never complicate things by "changing" it. I write up, order, and check in the Rx exactly as written. Plus Cyl, or Minus, whenever you make the decision to change it to something else you add a layer of complexity to what we do and also every change is a chance to screw things up. Keep it simple by leaving it alone.

Same here. I really have no reason to transpose, one way or the other. If I get an outside Rx that is + cyl, that's how I order it and inspect it. If I'm neutralizing, I read in -. When I worked for MD's, I'd neutralize in +.


The only time I transpose for myself is if I'm comparing an Rx to an older one, and they are written in opposite signs (written by different docs, for example). I want them both in - cyl so I can explain the difference (how much change) to the patient.

[Speed]

It is all the same. Write it anyway you feel most comfortable with.

[lensman78]

I work for an Ophthalmologist and all of his Rx's are written in plus cyl, except for ctl... none of the labs I use have had any problems, and RxWizard doesn't seen to care. When I ran an optical lab, the software we used didn't care either.

[mshimp]

Enter it in as written. most POS systems will not mater. Vision Express converts to minus cyl. or allows you to convert to plus cyl. When choosing base curves I like the RX in the minus form. I dont always care for the choice that surfacing programs select, so I do this on a regular basis.

[For-Life]

I am kicking myself in the butt, because I made an error this week. When I was on RX Club, I did the right with a plus cyl and the left with a minus (I did not convert. I just accidentally did it as a minus). Though, I am a little frustrated that they accepted it, considering that you really cannot do one lens in a plus cyl and one in the minus.

[chip anderson]

Actually you could do one plus and one minus cylinder, I have even done work for OMD's who wrote Rx this way on occasion.

Chip

Technically the plus one should have the cylinder ground on the front and the minus one on the back.

[For-Life]

yeah, but that really does not happen today. These were CR-39 so we know they just surfaced them.