ABO NOCE Basic Opticianry Spectacle Dispensing Procedures Questions and Answers 5

Question 1

What is the purpose of 'blocking' a lens during the fabrication process?

Accepted Answer

To secure the lens to a chuck for surfacing or edging at the correct optical center

Answer

Blocking attaches the lens blank to a holding device (block) so it can be processed with the optical center precisely positioned for surfacing or edging.

Question 2

A patient's old glasses have a base curve of 4.00 D. Their new prescription is filled on a 6.00 D base curve. The patient complains of distortion. The MOST likely cause is:

Accepted Answer

Adaptation difficulty due to change in lens form

Answer

A significant change in base curve alters the lens form, changing peripheral aberrations and causing adaptation issues for some patients.

Question 3

Which ANSI standard governs the tolerances for finished prescription spectacle lenses in the US?

Accepted Answer

ANSI Z80.1

Answer

ANSI Z80.1 establishes the prescription tolerances and optical requirements for finished ophthalmic lenses dispensed in the United States.

Question 4

When dispensing lenses with significant prism, the optical center placement is replaced by which reference point?

Accepted Answer

The prism reference point (PRP)

Answer

The prism reference point (PRP) is the location where prescribed prism is verified and placed relative to the pupil for lenses containing prism.

Question 5

A patient's frame has a B measurement of 32 mm and they require a flat-top 28 bifocal. The seg height is ordered at 17 mm. This placement positions the seg top:

Accepted Answer

Below the lower lid margin

Answer

With a 32 mm B measurement and 17 mm seg height, the segment top is 15 mm from the bottom, which typically falls at or just below the lower lid margin.

ABO NOCE Basic Opticianry Practice Test

ABO NOCE Basic Opticianry Practice Test

ABO NOCE Basic Opticianry Spectacle Dispensing Procedures Questions and Answers 5