Spectacle Dispensing Procedures Flashcards
7 cards from real NOCE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Spectacle Dispensing Procedures flashcards as text
When dispensing lenses with prescribed prism, the prism reference point (PRP) should be placed:
Answer: At the patient's pupil center in primary gaze
The prism reference point must coincide with the patient's pupil in primary gaze so the prescribed prism is fully effective.
A patient's complaint of 'ghost images' in a new single vision AR-coated lens most likely indicates:
Answer: Reflections from the back surface not fully suppressed
Ghost images in AR-coated lenses are caused by internal reflections—particularly from the back surface—that the coating did not fully eliminate.
During frame adjustment, 'X-ing' the temples refers to:
Answer: A condition where one temple is angled inward and the other outward, causing the frame to sit unevenly
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.
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:
Answer: Adjusted in power to compensate for the shorter vertex distance
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.
Which ANSI standard specifically governs the optical and physical performance requirements for prescription ophthalmic lenses in the United States?
Answer: ANSI Z80.1
ANSI Z80.1 sets the requirements for prescription ophthalmic lenses including power tolerances, prism tolerances, and optical quality in the US.
A patient with convergence insufficiency has been prescribed 2Δ base-in split between both lenses. If this is prescribed as slab-off, which lens receives the slab-off and in what direction?
Answer: Slab-off is not applicable for base-in prism
Slab-off is used to resolve vertical imbalance at near in bifocal wearers, not horizontal (base-in/out) prism; base-in prism is ground in or incorporated differently.
When using a hand neutralization technique to determine lens power, a 'with' motion of the cross-lines means the lens is:
Answer: Plus power
A 'with' motion (target appears to move in the same direction as the lens movement) indicates a plus lens during hand neutralization.