another basic question (this time about Prentice's Rule)

[moody]

This is pretty straight forward question so I'm not sure what I'm doing wrong.

question says

How many cms is a lens displaced if the patient is experiencing 2 diopters of prism BI on the left eye? RX is:

-12.00

-10.00

so I thought, since prism diopter=hcm X D,
it'd be 2D=hcm X (-12.00) for OD
and 2D=hcm X (-10.00) for OS

so I got 0.16 cm for OD or 16mm for OD
and 0.20cm for OS or 20mm for OS

But the correct answer says 17mm
What did I do wrong?

Another question I got wrong is this one.
7) A patient needs 2 Diopters of prism BU OD and 2 diopters of prism BD OS. How far do the lenses need to be moved to obtain this prism?

OD: -8.00

OS: +6.00

I got 2.5mm BU OD and 3.3mm BD OS

but the answer says 7) 1.25 mm down OD & 1.67 mm down OS

Why are the values half of what I got?

[drk]

The first question only asked about the left eye. Prism diopters = displacement (cm) x power (diopters). 2 = x (cm) x 10.00 D. 2/10 = 0.2 cm. You're right.

[drk]

Second question asks you about amount you need to move the lens, so the answer is in centimeters, not prism diopters.

[moody]

For the second question, my answer was in cm/mm, not diopters. Not sure what you saw. I wanted to know why the distance I found was twice what the answer said.

[drk]

I saw what you said before your edit?

[moody]

Not sure, but I edited the first question, because the first question I had said the correct answer was only one and then realized you said the question was only for the left eye. So I did edit that one. The second question wasn't edited. But either way, I'm still confused as to why my answer is twice that the correct answer should be.

(Or maybe you saw what I posted before I finalized my question. Not sure)

[moody]

@drk
And, also still I am not sure why the correct answer for the first question says 0.17cm when what I got is .20cm and you got the same. Perhaps the study guide answer is wrong?

[drk]

I think the guide is wrong.

[optical24/7]

This is pretty straight forward question so I'm not sure what I'm doing wrong.

question says

How many cms is a lens displaced if the patient is experiencing 2 diopters of prism BI on the left eye? RX is:

-12.00

-10.00

so I thought, since prism diopter=hcm X D,
it'd be 2D=hcm X (-12.00) for OD
and 2D=hcm X (-10.00) for OS

so I got 0.16 cm for OD or 16mm for OD
and 0.20cm for OS or 20mm for OS

But the correct answer says 17mm
What did I do wrong?

Another question I got wrong is this one.
7) A patient needs 2 Diopters of prism BU OD and 2 diopters of prism BD OS. How far do the lenses need to be moved to obtain this prism?

OD: -8.00

OS: +6.00

I got 2.5mm BU OD and 3.3mm BD OS

but the answer says 7) 1.25 mm down OD & 1.67 mm down OS

Why are the values half of what I got?

1. Either you didn’t write the question here exact as written in your text you are studying, or there are errors in what you are studying.
2. .20 cm’s is not 20 mm’s, it’s 2mm ( and .17cm’s are not 17 mm’s, it’s 1.7 mm’s.)

On question #1, the correct answer for the -12 is 1.7mm, for the -10 the correct answer is 2mm.

on question #2, Either you didn’t write it exactly as your study material, or it’s incorrect. The way it’s worded, you need 4D of prism imbalance, but it’s telling you how to create 2D of imbalance with that answer.

[wmcdonald]

Folks,
This poster is one who, like too many, have been placed in a position somewhere serving as a quasi-optician. They are completely self-taught and struggling. I know this is a board for Professionals, and they list themselves as such, but in reality, in their words to me, they are not even an apprentice. In the past, as many are aware, I'd be the FIRST one to jump on this. But something in this on tells me the poster has a sincere interest. I've offered to help! I hope we do as we have and support this individual.

Since I am here:
Some have emailed, asking where I have been. I became excessively frustrated with the entire community. Opticianry has floundered for too long, and I was close to calling it a day. But something happened! I was invited by lifelong friends to attend the OAA Leadership Conference. It was here in NC, so to visit people that mean a lot to me, we trekked up the mountain. I expected little, but I am proud to share that I was pleasantly surprised!

I met some young bloods, that have a sincere desire to make this a better place. To improve this profession that has meant so much to me. As I checked in, a young lady approached Kaye and I, and I didn't know her. But she had just posted on LinkedIn PROUDLY, that she had completed her Master's Certificate through the ABO! As usual, I sent her an atta-girl on the site. I investigated online and found a person with a solid educational background (MPH, etc.), and SHE CHOSE to be an Optician. It's folks like Cira Collins from Oregon, who is working to reinvigorate the association up there, we need to lead us to a future we can really be proud of! Se has started doing some lecturing at CE events, and I encourage you to see her!

I already knew Wesley Scott, new OUTSTANDING new President of the SC Association. He introduced me to the fabulous Jayne Sommers, another with a strong desire to push us up the hill. I met Kimberly Vohsen, starting a new Opticians Association in Missouri, Illinois and Indiana!

I left that meeting with a sense or renewal. In the coming months, I will be announcing some news related to Opticianry and education. I am going to seek out some of you who I know are very bright and want to help move us forward. Look for it! George, Brian, and others, you know I'm talking to you!

We have renewed leadership, and it's time to go back to work for this old boy!
I took us away from the original poster for a moment, but I do hope we can rally around this individual.

I wish you all the very best!

[moody]

Thank you for your reply. I was in a rush to post the problem I missed the "." between 2.0mm and 1.7mm. My mistake.

And these questions were from the opticianstudy.com website and the answers and questions were copied and pasted from the website so the wordings are as I found them. So I guess the website had the answers wrong.

As wmcdonald posted below, I work at a retail place where I was recently introduced to the optical department and found it to be very interesting so I searched online to see if I can learn on my own about this stuff. I do apologize if I am at the wrong place but I just had questions I couldn't figure out and needed a place to ask.

I appreciate all of your help and I will try to limit myself from posting basic questions.

[optical24/7]

Moody, feel free to ask questions. Like I posted, nobody’s born knowing anything, much less ophthalmic optics! Thank you for clarifying that you copied and pasted from the quiz section of that site. Its wording/answers are incorrect as written. That’s why I questioned the accuracy of the question. The exact wording is very important to getting a correct answer! Good luck in your future studies!

[wmcdonald]

Moody, you are in the right place! We have some really sharp Opticians and Optometrists here, and will help.

[Fezz]

Folks,
This poster is one who, like too many, have been placed in a position somewhere serving as a quasi-optician. They are completely self-taught and struggling. I know this is a board for Professionals, and they list themselves as such, but in reality, in their words to me, they are not even an apprentice. In the past, as many are aware, I'd be the FIRST one to jump on this. But something in this on tells me the poster has a sincere interest. I've offered to help! I hope we do as we have and support this individual.

Since I am here:
Some have emailed, asking where I have been. I became excessively frustrated with the entire community. Opticianry has floundered for too long, and I was close to calling it a day. But something happened! I was invited by lifelong friends to attend the OAA Leadership Conference. It was here in NC, so to visit people that mean a lot to me, we trekked up the mountain. I expected little, but I am proud to share that I was pleasantly surprised!

I met some young bloods, that have a sincere desire to make this a better place. To improve this profession that has meant so much to me. As I checked in, a young lady approached Kaye and I, and I didn't know her. But she had just posted on LinkedIn PROUDLY, that she had completed her Master's Certificate through the ABO! As usual, I sent her an atta-girl on the site. I investigated online and found a person with a solid educational background (MPH, etc.), and SHE CHOSE to be an Optician. It's folks like Cira Collins from Oregon, who is working to reinvigorate the association up there, we need to lead us to a future we can really be proud of! Se has started doing some lecturing at CE events, and I encourage you to see her!

I already knew Wesley Scott, new OUTSTANDING new President of the SC Association. He introduced me to the fabulous Jayne Sommers, another with a strong desire to push us up the hill. I met Kimberly Vohsen, starting a new Opticians Association in Missouri, Illinois and Indiana!

I left that meeting with a sense or renewal. In the coming months, I will be announcing some news related to Opticianry and education. I am going to seek out some of you who I know are very bright and want to help move us forward. Look for it! George, Brian, and others, you know I'm talking to you!

We have renewed leadership, and it's time to go back to work for this old boy!
I took us away from the original poster for a moment, but I do hope we can rally around this individual.

I wish you all the very best!

Great post! Nice to see the fire again Warren!

[Kwill212]

Thank you for your reply. I was in a rush to post the problem I missed the "." between 2.0mm and 1.7mm. My mistake.

And these questions were from the opticianstudy.com website and the answers and questions were copied and pasted from the website so the wordings are as I found them. So I guess the website had the answers wrong.

As wmcdonald posted below, I work at a retail place where I was recently introduced to the optical department and found it to be very interesting so I searched online to see if I can learn on my own about this stuff. I do apologize if I am at the wrong place but I just had questions I couldn't figure out and needed a place to ask.

I appreciate all of your help and I will try to limit myself from posting basic questions.

I clicked through some of their quizzes and found other errors. I would not use that site as a reference. Do you have a copy of System for Ophthalmic Dispensing? I was going to say 3rd edition but I see there is a new 4th edition just published a couple months ago. Either would be a fine start.

[moody]

I clicked through some of their quizzes and found other errors. I would not use that site as a reference. Do you have a copy of System for Ophthalmic Dispensing? I was going to say 3rd edition but I see there is a new 4th edition just published a couple months ago. Either would be a fine start.

Thank you. I was wondering if I should continue using the website as well. I just liked the website because it explained everything in layman's terms and I could actually understand. Anyways, I'll search for that book and see if I can buy that. Thanks for the advice.

[wmcdonald]

I hope we can make a difference! Thanks, Fezz!

[wmcdonald]

The book is exceptionally well written. Can you understand it all? Probably over time. But the important thing is to find someone you can go to for questions and support! We're out here in Mr. Gore's wonderful Internet, and ready, but one closer that can help guide you would be beneficial..