ABO NOCE Basic Opticianry Optical Instrumentation Use Questions and Answers 3

Question 1

When using a pupillometer to measure monocular PDs, what is the correct patient fixation target?

Accepted Answer

The instrument's internal fixation light for each eye separately

Answer

The patient fixates on the internal fixation light while each eye is measured separately to obtain accurate monocular PDs.

Question 2

Which of the following best describes the function of a frame warmer (frame heater)?

Accepted Answer

It softens plastic frames for adjustment without cracking

Answer

A frame warmer uses heat (salt pan, hot air, or infrared) to soften plastic acetate frames so they can be safely adjusted without cracking.

Question 3

An auto-lensometer differs from a manual lensometer primarily in that it:

Accepted Answer

Automatically determines sphere, cylinder, axis, and prism without manual wheel adjustments

Answer

An auto-lensometer (focimeter) electronically measures and displays all lens parameters automatically when the lens is placed on the lens stop.

Question 4

When verifying lenses with a lensometer, the cylinder power of a –2.00 –1.50 × 090 lens is measured by:

Accepted Answer

Noting the difference between the two drum readings when each set of lines clears

Answer

Cylinder power equals the algebraic difference between the two drum readings (first meridian minus second meridian) when each set of lines sharpens.

Question 5

A keratometer (ophthalmometer) is used to measure:

Accepted Answer

The curvature of the anterior corneal surface

Answer

The keratometer measures the radius of curvature of the anterior corneal surface, typically used for contact lens fitting.

ABO NOCE Basic Opticianry Practice Test