Spectacle Dispensing and Fitting 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 and Fitting Questions and Answers flashcards as text
What is the pantoscopic tilt and what is the standard recommended angle?
Answer: The vertical angle of the frame front; typically 8–12°
Pantoscopic tilt is the angle of the frame front in the vertical plane (bottom tilted toward the face). The standard is approximately 8–12 degrees.
When measuring monocular pupillary distance (PD), what is the correct procedure?
Answer: Measure from the center of the pupil to the center of the nose bridge for each eye separately
Monocular PD is measured from the center of each pupil to the center of the nose bridge, giving separate right and left measurements.
What is the vertex distance and why does it matter for prescriptions over ±4.00 D?
Answer: The distance from the back lens surface to the cornea; it affects effective lens power at the eye
Vertex distance is the distance from the back surface of the lens to the cornea. For powers over ±4.00 D, this distance significantly affects the effective power at the eye.
The facial measurement 'DBL' (distance between lenses) refers to:
Answer: The horizontal distance between the inner edges of the two lenses
DBL is the distance between lenses — the clear horizontal gap between the inner (nasal) edges of the two lenses in the frame.
Which frame adjustment is used to correct a frame that sits too high on the patient's nose?
Answer: Increase the splay angle of the nose pads to widen the pad spread
Splaying the nose pads outward (increasing pad splay) lowers the frame by widening the support base, dropping the frame to the correct position.
What is the 'effective diameter' of a lens and how is it used in lens ordering?
Answer: The diameter of the smallest circle that will contain the entire lens shape; used to determine minimum blank size
Effective diameter (ED) is the diameter of the smallest circle encompassing the full lens shape. Minimum blank size = ED + 2× decentration, ensuring the blank covers the entire finished lens.