ABO NOCE Basic Opticianry Optical Instrumentation Use 2

Question 1

When using a lensometer to verify a progressive addition lens (PAL), where should the distance zone reading be taken?

Accepted Answer

At the distance reference point (DRP) marked on the lens

Answer

At the geometric center of the lens

Answer

At the optical center dot

Answer

At the near reference point

Question 2

A Geneva lens clock (lens measure) reads +2.00 D on the front surface and -0.75 D on the back surface of a lens. What is the approximate through power?

Accepted Answer

+1.25 D

Answer

+2.75 D

Answer

-1.25 D

Answer

+2.00 D

Question 3

What does a PD meter (pupillometer) primarily measure?

Accepted Answer

The interpupillary distance

Answer

The vertex distance from the cornea to the lens

Answer

The base curve of the lens

Answer

The prism in a lens

Question 4

When neutralizing a lens with the lensometer, the power rings are brought to sharpest focus and the lines appear broken. This indicates the presence of:

Accepted Answer

Cylinder

Answer

Prism

Answer

Sphere only

Answer

Base curve error

Question 5

Which instrument is used to measure the base curve of a finished lens?

Accepted Answer

Geneva lens clock

Answer

Lensometer

Answer

Radiuscope

Answer

Focimeter

Question 6

A lensometer shows that a lens has 1.50 D of prism. If the dot is located below the 90° line, the prism is:

Accepted Answer

Base up

Answer

Base down

Answer

Base in

Answer

Base out

Question 7

The radiuscope is used primarily to measure:

Accepted Answer

The radius of curvature of a contact lens back surface

Answer

Lens power in diopters

Answer

Pupillary distance

Answer

Vertex distance