ABO NOCE Basic Opticianry Optical Instrumentation Use Questions and Answers 2

Question 1

When using a lensometer to measure a bifocal lens, where should the segment optical center be placed to read the add power?

Accepted Answer

Over the near segment optical center

Answer

Over the distance optical center

Answer

At the geometric center of the lens

Answer

At the temporal edge of the lens

Question 2

Which instrument is used to measure the curvature of the front and back surfaces of a contact lens?

Accepted Answer

Radiuscope

Answer

Lensometer

Answer

Keratometer

Answer

Pupillometer

Question 3

On a manual lensometer, the power drum is turned until the target lines are sharpest. What does a clear sphere target with blurred lines indicate?

Accepted Answer

There is cylinder power present

Answer

No cylinder power is present

Answer

Cylinder axis is misaligned

Answer

The lens is prismatic

Question 4

A lensometer reading shows that the target does not center in the eyepiece even when the lens is moved horizontally. This indicates the presence of:

Accepted Answer

Prism

Answer

Cylinder power

Answer

Sphere power

Answer

Add power

Question 5

What is the purpose of the ink dots placed on a lens after neutralization with a lensometer?

Accepted Answer

To mark the optical center and axis

Answer

To indicate the segment height

Answer

To show the progressive corridor

Answer

To mark the fitting cross

Question 6

When measuring progressive addition lenses (PALs) with a lensometer, the distance power is measured:

Accepted Answer

Through the distance zone in the upper portion

Answer

Through the near zone

Answer

Through the intermediate zone

Answer

At the geometric center of the lens

Question 7

A Geneva lens clock (lens gauge) measures:

Accepted Answer

The surface curvature of a lens in diopters

Answer

The refractive index of a lens

Answer

The overall lens thickness

Answer

The abbe value of the material