Spectacle Dispensing Procedures Questions and Answers Flashcards
6 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 6 Spectacle Dispensing Procedures Questions and Answers flashcards as text
When dispensing progressive addition lenses (PALs), the fitting cross should be positioned:
Answer: At the center of the pupil when the patient looks straight ahead in natural primary gaze
The progressive lens fitting cross (or fitting point) must align with the pupil center in primary gaze to ensure the patient looks through the correct zone of the lens for each distance.
What is the significance of the 'corridor length' in progressive addition lenses?
Answer: It is the vertical length of the progressive channel from distance zone to full add power; shorter corridors need more head movement
The corridor length is the vertical pathway of progressive power change from the distance reference point to the near reference point. Shorter corridors give less head movement but narrower zones.
The minimum fitting height for most standard progressive addition lenses is approximately:
Answer: 18–22 mm
Standard progressive lenses require a minimum fitting height of approximately 18–22 mm to accommodate the full corridor from distance to near zones.
When verifying the optical center placement of a dispensed pair of glasses, the optician should check:
Answer: That the OC height matches the prescribed seg/OC height and the horizontal decentration matches the patient's PD
Verification must confirm that optical centers are placed at the correct height and horizontal position (per patient PD) per ANSI Z80.1 standards.
Which of the following is the correct way to adjust the temple length on a metal frame?
Answer: Heat the temple bend area and reshape to move the bend point closer or farther from the hinge to change the length behind the ear
Temple length adjustment on metal frames involves heating the bend point and reshaping — moving the bend forward (shortening) or backward (lengthening) to fit the distance behind the patient's ear.
What is 'retroscopic tilt' and how does it affect the patient?
Answer: The top of the frame tilting toward the face (reverse of pantoscopic); it can cause unwanted oblique astigmatism and visual distortion
Retroscopic tilt (negative pantoscopic tilt) is when the top of the lens tilts toward the face. It induces unwanted astigmatic power and should be avoided.