Axis query.

[Mymyopia]

Hi everyone.

A quick question regarding how we write a prescription.

Does anyone ever write an axis with a decimal point on the end such as 10.0?

[Uncle Fester]

I can recall seeing an axis that specified out to a .5 once where the rx was +0.12 -0.12 x 25.5 O.U. so I think the prescriber was telling me someone wanted prescription glasses that really didn't need them. Technically I could make them with 0.00 lenses and be within tolerance.

All other rx's I've seen were written in whole numbers.

[mervinek]

nope. 3 digit number. like 180; 090; 005 etc

[DanLiv]

nope. 3 digit number. like 180; 090; 005 etc

Exactly. Writing 10.0 is just begging to be misinterpreted as 100. It should be written 010.

[Mymyopia]

Thats why I asked, back when I was in training I was told sphere and cyl must be to two decimal places and an axis must not have any decomal places.

I've had an optical advisor who's confused a 10.0 for 100 but I was the one who to him there would never be a decimal as it could be confusing.

I wish there was a standard format we could all agree on.

[NAICITPO]

Thats why I asked, back when I was in training I was told sphere and cyl must be to two decimal places and an axis must not have any decomal places.

I've had an optical advisor who's confused a 10.0 for 100 but I was the one who to him there would never be a decimal as it could be confusing.

I wish there was a standard format we could all agree on.

There is a format we all agree on, 010 is the easiest way to say 10 degrees without being misinterpreted. Anyone who writes axis 10 as 10.0 is just wrong, I have never seen a decimal place for an axis. I don't even think there is a phoropter/autorefractor that measures to the decimal place for axis.

[Robert Martellaro]

1/2 is ok if you dare, although it might make sense for very high cylinder values.

Don't use a degree sign ˚ at the end.

Hope this helps,

Robert Martellaro

[kriptok]

Anything I've ever seen has been in 3 places, 001, 010, 100, 110, 111, and so on, till back to 0/180 which may use the °

[CME4SPECS]

I filled this rx almost 7 years ago. I filled it as 70 on the right and 90 on the left. Had I not known his previous rx, I don't know what I would have done. It worked just fine for him. Note: this came from Great Britain.

[Mymyopia]

So while there is a format we would use, there's not an industry standard (in the UK) that we must use.

[NAICITPO]

What doctor is prescribing axis into the decimal place? Maybe an engineer turned optometrist, LOL?? Is the doc literally sitting there during refraction saying 1 with axis 90, and 2 with axis 89, and the patient says they are equal so the doc says I got it, 89.5?!? But why stop there? Why not go to quarter steps like we do for sphere and cyl? 89.25! What about 89.125?

You can't even measure to a decimal place on any manual lensometer I have worked with and even if you could to be off a half a degree in axis and that is well within tolerance for any Rx.

Maybe you can start a trend in the UK to change it from 9.0 to 009? Less confusion, less remakes.

[Mauro.Airoldi]

I try to clarify the numbers a little (ok I'm European and I don't use thumbs). in physics it is used to put the comma (or the dot) only as a function of the precision of the measurement of the physical quantity in question.
This means that if we measure a room, we will have a size measured in meters but we will stop at three digits after the decimal point because normal tape meters do not measure tenths of a millimeter. this means that the measure of a room will be for example 4,253 meters.
In the case of lenses, the instrumental precision of measurement is in the order of 0.01 D per sphere and cylinder but on the axes it is much lower, in the order of 1 degree. Furthermore, the regulations never go so far as to prescribe an accuracy of less than 5 degrees
Writing axis at 15.3 ° is non-measurable and not even required nonsense.

[waynegilpin]

Is the doc literally sitting there during refraction saying 1 with axis 90, and 2 with axis 89, and the patient says they are equal so the doc says I got it, 89.5?!?

When a speaker started bragging during mandatory continuing ed. about being able to surface to 1/100 D, I asked what the point of that was when refractions were done to .25D. Needless to say, he wasn't happy with the question. No gold star for me that day.

[Lensman11]

Actually being able to surface to a tolerance of 1/100 is important. It is the only variable the lab can control. If all the tolerances on an order move in the wrong direction you can have a problem you can’t control. As an example front surface tolerance 0.06 tooling tolerance 0.06 thickness tolerance 0.3 inspection equipment tolerance 0.12. This does not count index of the material which is never measured but does deviate. As well as pad thicknesses. Add these together and you have more than 0.25 error and you did nothing wrong. Fortunately this does not happen to often but taking out the tooling error will certainly keep you within tolerance all the time.

[Alex Camblor]

So while there is a format we would use, there's not an industry standard (in the UK) that we must use.

Good luck, we haven’t even standardized prescriptions written with plus or minus cyl.

[NAICITPO]

Good luck, we haven’t even standardized prescriptions written with plus or minus cyl.

I see what you are saying but the plus/minus cyl shouldn't bother you that much. If you can't do the simple math in your head to convert plus cyl to minus cyl or vice versa there are websites that can do that for you. I even have it bookmarked for our front desk people. Putting cyl like the way it was put 9.0, when it could mean 90 or 009 isn't a standard and is just asking for trouble. I understand why MD's write in plus cyl and OD's write in minus cyl, it's how they were taught to refract. But what reason could there be to write axis 009 as 9.0?

[KrystleClear]

I see what you are saying but the plus/minus cyl shouldn't bother you that much. If you can't do the simple math in your head to convert plus cyl to minus cyl or vice versa there are websites that can do that for you. I even have it bookmarked for our front desk people. Putting cyl like the way it was put 9.0, when it could mean 90 or 009 isn't a standard and is just asking for trouble. I understand why MD's write in plus cyl and OD's write in minus cyl, it's how they were taught to refract. But what reason could there be to write axis 009 as 9.0?

I don't mind transposing RXs, but as someone who works for an MD who prescribes in plus cyl, we have issues when our patients take their scripts elsewhere to be filled. Sometimes the person taking orders at the outside optical shop doesn't understand flat transposition or once the person wasn't aware what plus cyl was and called to question the script. Ugh. I worked for an optometry chain first and even they explained that to us, despite lacking in every other aspect of proper training.

[Uncle Fester]

Hijack alert!

"I don't mind transposing RXs, but as someone who works for an MD who prescribes in plus cyl, we have issues when our patients take their scripts elsewhere to be filled."

Was your doc taught a very old school way of writing an rx or challenging the patients the office doesn't capture?

Either way I don't see why today anyone has an issue as long as it is everywhere (including the internet) copied/ordered as written.

Am I remembering correctly from opticians school when we learned plus cyls were written by doc's because early glass spectacle lenses always had the cyl generated on the convex ("plus") side of the lens?

[NAICITPO]

Either way I don't see why today anyone has an issue as long as it is everywhere (including the internet) copied/ordered as written.

Yeah I always just enter a plus cyl Rx as plus cyl online unless I am going to be edging it myself. Let the lab computers figure it out, no way of messing it up.

[KrystleClear]

Hijack alert!

"I don't mind transposing RXs, but as someone who works for an MD who prescribes in plus cyl, we have issues when our patients take their scripts elsewhere to be filled."

Was your doc taught a very old school way of writing an rx or challenging the patients the office doesn't capture?

Either way I don't see why today anyone has an issue as long as it is everywhere (including the internet) copied/ordered as written.

Am I remembering correctly from opticians school when we learned plus cyls were written by doc's because early glass spectacle lenses always had the cyl generated on the convex ("plus") side of the lens?

I have yet to encounter an MD who writes their scripts in minus cyl, but I am sure trying to keep the patients here may be some motivation. I'm not going to complain about anything that deters an online order, either.

[mervinek]

I worked in a practice with 2 ophthalmologists (owners) and 1 optometrist and they all wrote in minus cyl. I now work in a practice with 1 ophthalmologist (owner) and 2 optometrists and they write in plus cyl. I remember hearing the OMD say how plus cyl just makes more sense and I remember my internal monologue crying Nooooooooooooo! Personally my brain will always like minus cyl better but I switch back and forth as needed. We have a lot of outside Rxs with minus cyls and we just put it in the computer as written, plus or minus. We order it as written to our lab and they fill it as written. It's really not a big deal. We are not a political dispensary. Plus cyl and minus cyl live together in harmony here.

[NAICITPO]

I worked in a practice with 2 ophthalmologists (owners) and 1 optometrist and they all wrote in minus cyl. I now work in a practice with 1 ophthalmologist (owner) and 2 optometrists and they write in plus cyl. I remember hearing the OMD say how plus cyl just makes more sense and I remember my internal monologue crying Nooooooooooooo! Personally my brain will always like minus cyl better but I switch back and forth as needed. We have a lot of outside Rxs with minus cyls and we just put it in the computer as written, plus or minus. We order it as written to our lab and they fill it as written. It's really not a big deal. We are not a political dispensary. Plus cyl and minus cyl live together in harmony here.

+1

I think plus cyl is harder to talk to patients about their reading rx. I get people coming from an opthalmologist's office trying to understand their reading rx and not getting why you have to add the cyl to the sphere and also add the add power to it. So it is a little bit harder to compare a plus cyl Rx to over the counter readers that most are familiar with. That's a strike against plus cyl to me but you are never going to convince either side to switch.

[finefocus]

+1

I think plus cyl is harder to talk to patients about their reading rx. I get people coming from an opthalmologist's office trying to understand their reading rx and not getting why you have to add the cyl to the sphere and also add the add power to it. So it is a little bit harder to compare a plus cyl Rx to over the counter readers that most are familiar with. That's a strike against plus cyl to me but you are never going to convince either side to switch.

A sphere equivalent is a sphere equivalent, whether in +cyl or -cyl. What's the difference?

[Uilleann]

So we've taken to measuring optical axis now in arcminutes and arcseconds? Whelp - that's me checking out. LOL

[Uncle Fester]

"Am I remembering correctly from opticians school when we learned plus cyls were written by doc's because early glass spectacle lenses always had the cyl generated on the convex ("plus") side of the lens?"

Can any old timers verify this memory?