Spectacle Dispensing and Fitting Questions and Answers Flashcards
7 cards from real ABO NOCE Basic Opticianry 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 and Fitting Questions and Answers flashcards as text
The minimum fitting height for a lined bifocal segment is typically measured from:
Answer: The lower lid margin to the bottom of the frame
Bifocal segment height is measured from the lower eyelid margin to the bottom of the lens (or frame groove), ensuring the segment line aligns properly.
A patient's spectacles show excessive 'four-point touch' contact on the face. This indicates:
Answer: The frame is too wide and requires endpiece adjustment
Four-point touch at the temples and nose simultaneously with the frame bowing in the middle indicates the frame is too wide for the patient's face.
Which lens material has the highest Abbe value, resulting in the least chromatic aberration?
Answer: CR-39 plastic (n=1.498)
CR-39 has an Abbe value of approximately 58, the highest among common ophthalmic lens materials, giving the least chromatic aberration.
When a patient reports that glasses feel tight on one side of the head only, the optician should first check:
Answer: The facial symmetry and temple alignment
Unilateral tightness often results from unequal temple spread or the patient's facial asymmetry requiring one temple to be adjusted differently.
In the boxing system, the 'datum line' is:
Answer: The horizontal line through the geometric center of the lens
The datum line is the horizontal line passing through the geometric center of the lens, used as the reference for vertical measurements in the boxing system.
A patient with a +4.00 D prescription requires glasses. Which nose pad style generally provides the best support for heavy high-plus lenses?
Answer: Adjustable silicone nose pads on a metal frame
Adjustable silicone nose pads on a metal frame allow precise positioning to distribute the weight of heavy plus lenses evenly and prevent slipping.
Decentration of a lens is used in opticianry to:
Answer: Position the optical center at the patient's pupil or to create prescribed prism
Decentration moves the optical center relative to the geometric center of the lens to align with the patient's PD or to induce prismatic effect.