# ABO Review Quiz 3 – Lens Form

ABO Review Quiz - Lens Form
OpenOptix ABO Study Guide: Chapter 3
31 Questions

A lens clock is used to measure

Transpose the following prescription: +2.25 +1.75 X 085

Equiconcave, flat concave, and meniscus are ALL types of

Equiconvex, flat convex, and meniscus are ALL types of:

The reason for using a "best form" lens is to minimize

A lens has a front surface power of +2.00D and a back surface power of -8.25D. The corrective power is

What is the best base curve for a -3.75D lens?

Using the prescription +2.00 -1.50 X 45, what is the power of the lens at the 90th meridian?

How much cylinder power is in effect at the specified axis?

A plus lens

A minus lens

Transpose the following prescription: -0.75 +3.00 X 180

Using the prescription -1.00 -1.50 X 90, what is the power of the lens at the 180th meridian?

What is the best base curve for a +2.50D lens?

Eyeglass prescription powers are written in _________.

Axis is ____________.

To switch between minus and plus cylinder forms we use _____.

Plus lenses ________ and minus lenses ________.

The spherical equivalent of the lens +1.00 +2.50 x 90 is:

If the prescription is O.D. +1.00 +2.50 x 45, what would be the total power at axis 90?

Which of the following lenses has no power in the 90

Given an Rx with all specifications equal but ground in material of different indices, which set of lenses will be the thinnest?

A lens having one concave and one convex surface is called a __________ lens.

The dioptric difference between the lenses for the prescription of O.D. +2.00 sph, O.S. +0.50 sph would be:

Astigmatism is corrected by a lens having:

Given the prescription +1.00 +1.00 axis 90, how much of the +1.00 cylinder is in effect at axis 90 (the vertical meridian of the lens)?

A myope always has in his or her prescription the following kind of power:

A hyperope always has in his or her prescription the following power:

If a +10D lens is moved 5 mm nearer the eye, it will be about:

The relationship of front and back curvatures on a spectacle lens will determine:

How much cylinder power is in effect 90 degrees away from the specified axis?

1. Question #5 is incomplete.

2. What is the best base curve for a +2.50D lens?
Shouldn’t that be 8.5 not 8? If you add 6 to the sphere power.

• +2.50/2 + 6.00 = 7.25 (8.00 is the closes)

3. Can anyone explain the simple way of understanding how to determine the effective powers at any meridian and a cylinder power. I DO NOT KNOW THE STEPS IF THERE IS. I am taking the ABO Exam this May 20,2012. GOD HELP ME!

4. Q5 is incompleate… the q is The reason for using a “best form” lens is to minimize _________.

• Thanks Lisa! It’s now fixed.

5. To k13, if you do cross cilinder you get (-1.00 x 180) (-2.50 x 90). Why is the answer -2.50?

6. I WAS WONDERING HOW COME ON NUMBER 9 THE ANSWER IS 0%?
IF YOU DO THE PROBLEM…90TH MERIDIAN-45 SPECIFIED AXIS IS 45…AND 45 DEGREES IN A KEY PERCENTAGE CONVERTS TO 50% OF THE CYLINDER POWER…WOULDN’T 50% BE THE ANSWER? NO 0%? IF IT IS 0%..I JUST WANTED TO MAKE SURE WHY…I HAVE THE TEST IN 2 WEEKS AND IT WOULD BE VERY HELPFUL THANK YOU

• This one got me too. The wording is kind of tricky. I thought that when they said “specified axis” they meant the one they were asking about in the previous question, i.e. the 90th meridian. But what the question actually refers to is the axis specified by the RX, i.e. the 45th meridian. Tricky one.

7. There are 2 questions listed regarding cylinder power. The 1st question asks about cylinder power at the specified axis with the answer – 100%. The 2nd question asks the cylinder power at 90 degrees away from the specified axis with the answer – 100%. Which is correct?