# Thread: Take a Master Exam

1. ## Take a Master Exam

Okay, while we're on the subject of the ABO's Master in Ophthalmic Optics Exam, I have provided a practice test, below. These sample questions are similar to many of the questions from the actual Master Exam I took. (No one really offered practice questions back then though, which made preparation especially difficult.) For those interested in trying some of these questions out, I'll post the answers in a few days so you can see how well you did.

Practice Master Exam

1. Prism-thinning is most often done to reduce thickness in what type of lens?
a. Minus-powered progressive lenses
b. Plus-powered progressive lenses
c. Flat-top bifocal lenses
d. Minus-powered single vision lenses

2. Which spectacle wearer has to accommodate more for a giving working/reading distance?
a. Myope
b. Hyperope
c. Emmetrope
d. They accommodate the same

3. Given a spectacle prescription for a right lens that requires 2D base in, 1.5D at 30, and 0.75D at 60, what would be the resultant prism?
a. 3.93D at 21°
b. 3.93D at 159°
c. 2.75D at 30°
d. 2.75D at 45°

4. If your lens measure reads +6.00 D while measuring the front curve of a 1.66 high-index plastic lens, what is the actual refractive power of the lens surface?
a. +4.82 D
b. +6.00 D
c. +7.47 D
d. +6.25 D

5. What kind of prism can be incorporated into single vision aspheric lenses without significantly affecting lens performance?
a. All prism
b. Prescribed prism
c. Prism for decentration
d. No prism

6. Which spectacle wearer enjoys the widest field of view through his or her lenses?
a. Myope
b. Hyperope
c. Emmetrope
d. They are the same

7. Which organization or agency requires a minimum thickness for dress (non-safety) spectacle lenses?
a. FDA
b. ANSI
c. OSHA
d. None of the above

8. An object 50 cm in front of a +5.00 D lens will come to a focus at what distance from the lens?
a. 25.0 cm in front of the lens
b. 33.3 cm behind the lens
c. 33.3 cm in front of the lens
d. 20.0 cm behind the lens

9. What is the sagitta—or depth—of a 6.00 D curve at 50 mm (assuming a refractive index of 1.530)?
a. 2.8 mm
b. 3.0 mm
c. 3.6 mm
d. 4.5 mm

10. Given a prescription of +10.00 D prescribed at a vertex distance of 13.5 mm, what lens power would be ordered for a vertex distance of 8.5 mm?
a. +10.50 D
b. +9.50 D
c. +10.25 D
d. +9.25 D

11. What type of prescription could be used to make a prosthetic eye appear higher in a depressed socket?
a. Minus cylinder at axis 180
b. Plus cylinder at axis 180
c. Base down prism
d. Base up prism

12. Corrected curve lenses generally reduce what type of lens aberration?
a. Diffraction
b. Spherical aberration
c. Chromatic aberration
d. Oblique astigmatism

13. The reflected images seen from the cornea and crystalline lens are referred to as?
a. Purkinje images
b. After images
c. Aerial images
d. Ghost images

14. The chromatic aberration in the periphery of a spectacle lens is?
a. Directly proportional to the power of the lens
b. Directly proportional to the distance from the optical center
c. Inversely proportional to the Abbe value of the material
d. All of the above

15. Given the following FT-35 bifocal prescription:
+2.00 DS with a +2.50 D add, O.U. (both eyes)
PD’s = 66/62 mm
How could you induce a 1D base in prismatic effect, per eye, at near only?
a. Use a 56 mm distance PD
b. Use a 60 mm near PD
c. Use a 54 mm near PD
d. Can’t be done

16. The transmittance of a Transitions photochromic plastic lens will not depend upon which factor?
a. Lens thickness
b. Temperature
c. Sunlight exposure
d. Age

17. Given the following single vision prescription:
-5.00 DS with 1.5D base in prism, O.U. (both eyes)
PD = 64 mm
Frame eyesize = 54 mm, bridge size= 16 mm, and effective diameter = 64 mm
What would be the minimum blank size required for a finished, stock lens (assuming a 1 mm allowance)?
a. 71 mm
b. 65 mm
c. 68 mm
d. 77 mm

18. A normal eye is most sensitive to which of the following colors during photopic (daylight) vision?
a. Red
b. Blue
c. Green
d. Equally sensitive

19. What is the focal length of a +5.00 D lens?
a. 5.0 m
b. 0.2 cm
c. 25 cm
d. 20 cm

20. If a near PD of 64 is specified for a pair of bifocal lenses with plano distance powers, and the segments are actually fabricated to a near PD of 60, what kind of prism is induced while reading?
a. Base in prism
b. Base out prism
c. Vertical prism
d. No prism

21. What is the ANSI tolerance on the near PD for multifocal segments?
a. 1.5 mm
b. 2.0 mm
c. 2.5 mm
d. 3.0 mm

22. When a lens is tilted, what prescription changes occur?
a. Sphere power is increased; cylinder power equal in sign to sphere power is induced
b. Only cylinder power is induced
c. Sphere power is decreased; cylinder power equal in sign to sphere power is induced
d. Sphere power is increased; cylinder power opposite in sign to sphere power is induced

23. Given an Rx for 4D Base In and 4D Base Up in the right eye (O.D.), what would generally be an acceptable way to split this prism in order to improve cosmetics and comfort?
a. O.D. 4D Base In and 4D Up; O.S. No prism
b. O.D. 2D Base In and 2D Up; O.S. 2D Base Out and 2D Base Down
c. O.D. 2D Base In and 2D Up; O.S. 2D Base In and 2D Base Up
d. O.D. 2D Base In and 2D Up; O.S. 2D Base In and 2D Base Down

24. Which of the following frames will return to its original shape when reheated?
a. Optyl
b. Cellulose Acetate
c. Carbon Fiber
d. Polyamide

25. What is the approximate overall refractive power of a typical human eye?
a. 17 D
b. 43 D
c. 60 D
d. 65 D

26. When the eyes focus on a near object, which of the following processes occur?
a. Eyes converge
b. Lenses accommodate
c. Pupils constrict
d. All of the above

27. Given a distance correction of O.D. +2.00 DS and O.S. +4.00 DS, which eye/lens would have the reverse slab-off applied for a vertical imbalance correction?
a. Right (O.D.) eye/lens
b. Left (O.S.) eye/lens
c. Either lens could use it
d. Neither lens could use it

28. A hard resin lens (CR-39, n = 1.500) loses approximately what percentage of light at each surface due to reflection?
a. 3.5%
b. 4.0%
c. 4.5%
d. 8.0%

29. What is the spherical equivalent of a lens with a power of +1.00 DS -2.00 DC × 180?
a. +1.00 D
b. +0.50 D
c. 0.00 D (plano)
d. -1.00 D

30. A “Hi-Drop” lens would most likely be used for what type of vision condition?
a. Partial sight (low vision)
b. Aphakia
c. Aniseikonia
d. Nystagmus

31. How far should the optical centers of a high-powered lens be placed above or below the pupil for every 2 degrees of pantoscopic tilt?
a. 1 mm above
b. ½ mm below
c. 1 mm below
d. 2 mm below

32. What is the cylinder power of a lens with a front curve of +4.00 D and back curves of -6.50 D and -8.00 D?
a. -1.50 D
b. -4.00 D
c. -2.50 D
d. +2.50 D

33. What is the ANSI Z80.1 tolerance on center thickness when specified?
a. +/-0.25 mm
b. +/-0.30 mm
c. +/-0.50 mm
d. +/-1.00 mm

2. damn it where are the answers!!!!

3. Okay, but don't look until you've tried to answer the questions:
.
.
.
.
.
.
.
.
1. b
2. b
3. a
4. c
5. b
6. a
7. d
8. b
9. c
10. a
11. c
12. d
13. a
14. d
15. c
16. a
17. b
18. c
19. d
20. a
21. c
22. a
23. d
24. a
25. c
26. d
27. b
28. b
29. c
30. b
31. c
32. a
33. b

4. Darryl, this was absolutely great... would you do another?

I really made me realize how much more i need to study

5. Darryl

You so rock:) Thanks for a great study guide. You actually stumped my doctor with some of the questions:hammer:

Christina

6. Thanks for a great study guide

Darryl, this was absolutely great... would you do another?
Well, maybe down the road. As you can imagine, it takes a bit to put something like this together. ;) I actually developed most of this particular test over ten years ago for a Master Exam Review Course I gave. Maybe I'll add a few more questions to round it to an even 50 over the weekend.

I really made me realize how much more i need to study
The Master Exam has apparently been watered down a lot in terms of its technical content. So, if you can get through a test like this, you should be able to sail through the ophthalmic optics portion of the examination. Don't let this discourage you.

Personally, I had no idea what to expect when I took the Master Exam, and really prepared more than I needed. I went through all of the ABO's suggested reading materials thoroughly, which cost me a great deal of time and money. Several were even out-of-print. However, I now have a formidable optical library because of it:

Where Darryl's Early Paychecks Went

I got several of these signed by the authors, which I think is neat. In any event, I guess it's better to be too prepared than ill prepared. Frankly, Brooks & Borish's System for Ophthalmic Dispensing, 2nd Ed would have been the only book needed to answer the majority of the questions from the old Master Exam.

By the way, each question on this practice test is worth about 3 percentage points, so you would need to get at least 23 of the questions right to pass a 100-question exam at 70%.

7. Great work Darryl......nice to have some material to refresh ourselves. Many thanks!!

Isn't the answer (b) for question #27?

27. Given a distance correction of O.D. +2.00 DS and O.S. +4.00 DS, which eye/lens would have the reverse slab-off applied for a vertical imbalance correction?
a. Right (O.D.) eye/lens

b. Left (O.S.) eye/lens
c. Either lens could use it
d. Neither lens could use it

8. Isn't the answer (b) for question #27?
Oops, Yes, Sorry. Unfortunately, I prepared my answer key rather haphazardly on a separate sheet of paper. I'll go through and double-check the rest right now to ensure I haven't transposed any other answers.

9. Gees Darryl,

It certainly does look like the old exam we did. There were also several questions regarding one problem that required answering several questions and if you make an error on one you would miss several.

I wrote several items for the NAO Masters Review book too.This brought back some of those memories. One I can remember was converting radius to diopters. There was no use of preprogramed calculators either.

I still have many Optical Index magazines that asked questions like this and taught you how to solve problems. Nothing is like it out there today.

Bev

10. I double-checked all of the problems, and the answer key is correct. I fixed the answer key for 27, too; it turns out I had added "reverse" to the original question when posting it here, but forgot to change the original answer in my key.

I still have many Optical Index magazines that asked questions like this and taught you how to solve problems. Nothing is like it out there today.
In the US, anyway. The British opticianry exams make this stuff look like a warm-up exercise. (To give you an idea, I pulled Question 3 from a British test.) I'll add a few British questions over the weekend to challenge even current Master Opticians a little.

I wrote several items for the NAO Masters Review book too
Perhaps you should post a few here...? Actually, e-mail them to me and I'll make a test form people can fill out to find out their answers instantly.

11. It's awesome to see this type of thread. Keep them coming!!!

12. I was scanning this practice test exam and one of the problems has me stumped. Question 3. The vertical and horizontal components are not given so you can't solve the problem simply using Pythagoras theorem. So how would you go about solving this problem?

13. When I was studying for the advanced test I went through Darryl practice questions as well and was stumped by that very question. It's a little easier than you may expect. Sad thing is I can't remember it right now!! My Nyquil induced drowsiness isn't helping me! But this is an important problem to understand, it came up countless times in my test! Darryl was kind enough to explain it and maybe Darryl, Harry or Lensgrinder can shed a little more light on this than I can at this time. Now my pillow is calling me!:D

14. Originally Posted by Darryl Meister
3. Given a spectacle prescription for a right lens that requires 2D base in, 1.5D at 30, and 0.75D at 60, what would be the resultant prism?
a. 3.93D at 21°
b. 3.93D at 159°
c. 2.75D at 30°
d. 2.75D at 45°
You could do it graphically drawing vectors, or the more simple solution would be to use the resolving prism formula

Vertical Prism = Prism * Sin (a)
Horizontal Prism = Prism * Cos (a)

so for the the first prism:

H=2 BI

for the second prism:

V=1.5*sin(30)=0.75BU (for right lens 30 degrees is nasal and above datum)
H=1.5*cos(30)=1.30BI

For the third prism:

V=0.75*sin(60)=0.65BU (for right lens 60 degreesis nasal and above datum)
H=0.75*cos(60)=0.38BI

Now we add them all together

V=0.75+0.65=1.40BU
H=2.00+1.30+0.38=3.68BI

Now we an use pythagoron theorem:

P2=V2+H2
P2=1.96+13.54
P=3.94

tan(a)=V/H
tan(a)=1.4/3.68
tan(a)=0.38
a=tan-1(0.38)
a=21

so 3.94@21 (so I rounded sue me):D Hey Donn lay off the nyquil cocktails.:p

15. Ahhh now I get it. Each prism is its own separate vector!! I was reading too much into the question and I confused myself. Once again, thanks Harry for helping me out with the question.

16. [quote=HarryChiling;208377]

... for the second prism:

V=1.5*sin(30)=0.75BU (for right lens 30 degrees is nasal and above datum)
H=1.5*cos(30)=1.30BI

For the third prism:

V=0.75*sin(60)=0.65BU (for right lens 60 degreesis nasal and above datum)
H=0.75*cos(60)=0.38BI

Maybe this is a browser problem ?

Internet Explorer:
[font=Times New Roman]3. Given a spectacle prescription for a right lens that requires 2D base in, 1.5D at 30, and 0.75D at 60, what would be the resultant prism?
a. 3.93D at 21&#176;
b. 3.93D at 159&#176;
c. 2.75D at 30&#176;
d. 2.75D at 45&#176;

Firefox:
3. Given a spectacle prescription for a right lens that requires 2D base in, 1.5D at 30, and 0.75D at 60, what would be the resultant prism?
a. 3.93D at 21&#176;
b. 3.93D at 159&#176;
c. 2.75D at 30&#176;
d. 2.75D at 45&#176;

The symbol for the prism in Firefox is translated as a "D". When I first read the Quote by Harry I read the prism as DOWN. I thought there was a mistake, then I checked IE. This could have caused some confusion.

I just realized this post does not make sense unless it is viewed in Internet Explorer.

17. Well I just took the test. I cannot believe I got the same exact version of the one I took in May in San Diego.

I was preparing for this exam anticipating taking a more technical version of the test. After all I thought that there were three versions, so I studied up on image formations, more of the equations, but lo and behold it was the same exact versions. Over 30 of the questions had to deal with management questions. Oh well I don't think that I passed so I'll take it again next May!!

Did anybody else experience the same thing?

18. ## Management questions

Yes Roland
I took the test a couple years ago and had a similar experience to yours. There was one question about some kind of accounting or business method and I haven't been able to find anything anything about that in the literature. I understand trying to make the test hard but using outdated references is questionable.

:)

20. ## Can you point me in the right direction

Hi Daryl,

I am new to Optiboard and currently studying to take the Advanced ABO exam in November. I am trying to figure out what to study to be able to answer queston 4, 8 and 19. Forgive me for asking something that is probably so obvious. I tried to figure out it out on my own...no luck.

Originally Posted by Darryl Meister
Practice Master Exam...
4. If your lens measure reads +6.00 D while measuring the front curve of a 1.66 high-index plastic lens, what is the actual refractive power of the lens surface?
8. An object 50 cm in front of a +5.00 D lens will come to a focus at what distance from the lens?
19. What is the focal length of a +5.00 D lens?

21. I am trying to figure out what to study to be able to answer queston 4, 8 and 19.
Optin, Any decent textbook on ophthalmic optics will cover these formulas, although for the original ABO Master Exam, I generally recommended System for Ophthalmic Dispensing. This is a comprehensive reference that every optician should own, in my opinion.

That said, this practice test was based upon the original ABO Master Exam, which focused much more on ophthalmic and geometrical optics than the current ABO Advanced Certification exam. The current exam covers more topics, like business management, but the actual optics questions are generally less difficult.

For the new ABO Advanced Exam, I usually recommend reviewing the NAO Advanced Opticians Tutorial, which provides content that applies directly to the questions on the ABO Advanced Exam. This book is fairly expensive, so you may try to locate a used copy, if the cost is an issue.

Best regards,
Darryl

22. ## Which principals or formulas

Originally Posted by optin
Hi Daryl,

I am new to Optiboard and currently studying to take the Advanced ABO exam in November. I am trying to figure out what to study to be able to answer queston 4, 8 and 19. Forgive me for asking something that is probably so obvious. I tried to figure out it out on my own...no luck.

[/FONT]
Hi again thank you for the feedback; can you narrow it down for me a little. For example; to get the distance that the image will be if the object is 50cm in front of a +5.00 diopter lens; would I use the 1/f = 1/p + 1/q where f = focal length, p = object and q = image

By the way I have read all of your Opti campus courses and some that I found on line that you did for Zeiss. Actually I should say that I have read them over and over because there is alot to comprehend. I woke up one day and decided that if I am an Optician then I should understand the visual system and how a lens affects vision. It is way to easy to just fill an order. I really want to understand what is happening in the eye and when I put a lens in front of it. So I will get this all down; probably never to the extent of someone like yourself. I appreciate anything that can shorten the learning curve especially since I committed myself to this Advanced Test.

I figured out #19 forgot to convert to cm, please tell me the formula to determne refractive surface power if the know variable are D+6.00 and n=1.66
Best Regards and Thank You

23. Hi again thank you for the feedback; can you narrow it down for me a little. For example; to get the distance that the image will be if the object is 50cm in front of a +5.00 diopter lens
Using the common optical sign convention, you can solve this problem using the following equation, known as the Conjugate Foci formula:

$L'=L+F$

Or, substituting the reciprocal object (l) and image (l') distances for the vergences,

$\frac{1}{l'}=\frac{1}{l}+F$
$\frac{1}{l'}=\frac{1}{-0.50}+5.00=+3.00$
$l'=\frac{1}{+3.00}=0.333$

where l is equal to -0.50 m, since the object is 50 cm in front of the wearer, and l' is equal to +0.333 m, which is 33.3 cm behind the lens. Note that your equation is also the Conjugate Foci formula, but based upon a different sign convention.

If your lens measure reads +6.00 D while measuring the front curve of a 1.66 high-index plastic lens, what is the actual refractive power of the lens surface
Since the lens measure or lens clock is typically calibrated to a refractive index of 1.530, known as the "tooling" index, you can solve this problem using the following equation to convert surface power from the tooling index to the actual refractive index of the lens material, assuming that the actual physical curvature hasn't changed:

$F_{ACTUAL}=\frac{n-1}{1.530-1}\times F_{READING}$
$F_{ACTUAL}=\frac{1.66-1}{0.530}\times 6.00$
$F_{ACTUAL}=7.47 D$

where FREADING is the reading of 6.00 from the lens measure and the refractive index n is 1.66.

Best regards,
Darryl

24. I can't thank you enough. You saved me hours and maybe even days trying to figure it out on my own. I don't think I will forget this after so much struggle to figure it out.

25. ## Review materials for Advanced Exam

Originally Posted by Darryl Meister
Using the common optical sign convention, you can solve this problem using the following equation, known as the Conjugate Foci formula:

$L'=L+F$

Or, substituting the reciprocal object (l) and image (l') distances for the vergences,

$\frac{1}{l'}=\frac{1}{l}+F$
$\frac{1}{l'}=\frac{1}{-0.50}+5.00=+3.00$
$l'=\frac{1}{+3.00}=0.333$

where l is equal to -0.50 m, since the object is 50 cm in front of the wearer, and l' is equal to +0.333 m, which is 33.3 cm behind the lens. Note that your equation is also the Conjugate Foci formula, but based upon a different sign convention.

Since the lens measure or lens clock is typically calibrated to a refractive index of 1.530, known as the "tooling" index, you can solve this problem using the following equation to convert surface power from the tooling index to the actual refractive index of the lens material, assuming that the actual physical curvature hasn't changed:

$F_{ACTUAL}=\frac{n-1}{1.530-1}\times F_{READING}$
$F_{ACTUAL}=\frac{1.66-1}{0.530}\times 6.00$
$F_{ACTUAL}=7.47 D$

where FREADING is the reading of 6.00 from the lens measure and the refractive index n is 1.66.

Best regards,
Darryl
I took this formula from the NAO Math Review book and no-where is it refered to as the conjugate foci formula nor is there any reference to it in the NAO Advanced Opticians Tutorial. Your Ray Tracing C.E. course at the Opti Campus site makes it very clear.
http://www.opticampus.com/cecourse.php?url=ray_tracing/
I have ordered Ellen Stoners Optical Formulas Tutorial hopefully it is referenced there and with the common sign convention. I just want to understand how to evaluate and solve the requirement or problems and which formula gets the job done. Otherwise I will be thrown when I take the test and the same terminology or sign convention is not used. I am putting these comments on because I assume that others who plan to sit for the Advanced Exam will find value here. The Advanced Opticians Tutorial is a fine review source for everything but geometric optics and lens design. If the optical formulas tutorial by Stoner is not sufficient then I will order the Opthalmic Guide to Dispensing since it receives high reviews. I have been avoiding spending the money and yet I have wasted almost as much on these other sources.

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