NOCE Spectacle Dispensing Procedures 5

Question 1

When dispensing lenses with prescribed prism, the prism reference point (PRP) should be placed:

Accepted Answer

At the patient's pupil center in primary gaze

Answer

The prism reference point must coincide with the patient's pupil in primary gaze so the prescribed prism is fully effective.

Question 2

A patient's complaint of 'ghost images' in a new single vision AR-coated lens most likely indicates:

Accepted Answer

Reflections from the back surface not fully suppressed

Answer

Ghost images in AR-coated lenses are caused by internal reflections—particularly from the back surface—that the coating did not fully eliminate.

Question 3

During frame adjustment, 'X-ing' the temples refers to:

Accepted Answer

A condition where one temple is angled inward and the other outward, causing the frame to sit unevenly

Answer

X-ing occurs when temples are angled asymmetrically—one in and one out—preventing the frame from lying flat on a table and causing an uneven fit.

Question 4

For a patient with a vertex distance of 14mm measured during the refraction, but the dispensed frame sits at 10mm, lenses with powers greater than ±4.00 D should be:

Accepted Answer

Adjusted in power to compensate for the shorter vertex distance

Answer

A change in vertex distance alters the effective power reaching the eye, so lenses stronger than ±4.00 D should be recalculated using the vertex compensation formula.

Question 5

Which ANSI standard specifically governs the optical and physical performance requirements for prescription ophthalmic lenses in the United States?

Accepted Answer

ANSI Z80.1

Answer

ANSI Z80.1 sets the requirements for prescription ophthalmic lenses including power tolerances, prism tolerances, and optical quality in the US.

NOCE - National Opticianry Competency Examination Practice Test

NOCE - National Opticianry Competency Examination Practice Test

NOCE Spectacle Dispensing Procedures 5