ABO NOCE Basic Opticianry Dispensing Instrumentation Questions and Answers 3

Question 1

Which of the following tools is specifically designed to measure the thickness of a spectacle lens?

Accepted Answer

Lens thickness gauge (caliper)

Answer

A lens thickness gauge or caliper directly measures the physical thickness of a lens at any specified point.

Question 2

When using a lensmeter to measure a bifocal lens, the reading through the segment gives the:

Accepted Answer

Near power only

Answer

Reading through the bifocal segment on the lensometer yields the total near power; the add power is calculated as near power minus distance power.

Question 3

The marking dots applied by the lensometer's ink marking device indicate the:

Accepted Answer

Optical center location and axis orientation

Answer

The three dots marked by the lensometer's marker show the optical center (center dot) and the horizontal reference axis (outer dots) of the lens.

Question 4

A frame aligner (frame alignment tool) is most useful for correcting:

Accepted Answer

Pantoscopic tilt and face-form angle of frames

Answer

Frame aligners allow the dispenser to measure and correct pantoscopic tilt and face-form wrap to ensure proper fit and optical performance.

Question 5

In lensometry, the difference in drum readings between the two focal lines of a cylindrical lens indicates the:

Accepted Answer

Cylinder power

Answer

The numerical difference between the two power drum readings when each focal line is clear represents the cylinder power of the lens.

ABO NOCE Basic Opticianry Practice Test