ABO NOCE Basic Opticianry Spectacle Dispensing Procedures 3 — Questions and Answers
Question 1: Pantoscopic tilt refers to the angle formed between the lens plane and:
- The horizontal plane of the floor
- A vertical plane perpendicular to the line of sight (Correct answer)
- The temporal bone
- The bridge of the nose
Correct answer: A vertical plane perpendicular to the line of sight
Pantoscopic tilt is the forward tilt of the lens plane measured from a vertical reference, typically 8–12° for most prescriptions.
Question 2: A patient's glasses slide down constantly despite proper nose pad adjustment. The most effective additional correction is:
- Add retaining cable temples (Correct answer)
- Decrease the pantoscopic tilt
- Reduce the frame's total weight
- Increase the vertex distance
Correct answer: Add retaining cable temples
Cable temples wrap around the ear, providing secure retention and preventing the frame from sliding on the face.
Question 3: When verifying a finished lens using a lensometer, the sphere power is read when:
- Both sets of lines are clear simultaneously
- Only the vertical lines are clear
- The target is centered and the sphere lines are clear (Correct answer)
- Only the horizontal lines are clear
Correct answer: The target is centered and the sphere lines are clear
In a manual lensometer, sphere power is confirmed when the sphere lines (one set) are brought into sharp focus with the target centered in the reticle.
Question 4: For a patient with a high minus prescription, which frame characteristic minimizes edge thickness?
- Large eye size with a low bridge
- Small eye size with centered PD (Correct answer)
- Full-rim plastic frame with large eye size
- Rimless frame with large eye size
Correct answer: Small eye size with centered PD
A small eye size minimizes the distance from the optical center to the edge, directly reducing edge thickness for minus lenses.
Question 5: When checking the fit of a newly dispensed frame, the optician observes the temples are diverging (spreading apart) behind the ears. This is corrected by:
- Heating and narrowing the end pieces
- Bending the temples inward at the bend (Correct answer)
- Decreasing the pantoscopic tilt
- Lengthening the temples
Correct answer: Bending the temples inward at the bend
Bending the temple tips inward at the bend point creates inward tension, preventing the frame from spreading and improving retention.
Question 6: The Boxing System for measuring lenses uses:
- The distance between the nasal and temporal edges of the lens
- A box enclosing the lens with horizontal and vertical dimensions (Correct answer)
- The chord diameter of the lens blank
- The effective diameter of the lens
Correct answer: A box enclosing the lens with horizontal and vertical dimensions
The Boxing System uses the smallest enclosing rectangle (box) around the lens shape, with eye size = horizontal width and B measurement = vertical depth.
Question 7: A patient reports intermittent double vision when reading after receiving new progressive lenses. The most likely dispensing cause is:
- Incorrect segment height — corridor too high
- Vertex distance too short
- The near PD is set too wide (Correct answer)
- Incorrect pantoscopic tilt angle
Correct answer: The near PD is set too wide
If the near PD is too wide, the patient's eyes must converge more than expected through the reading zone, causing binocular stress and possible diplopia.
ABO NOCE Basic Opticianry Spectacle Dispensing Procedures 3
Pantoscopic tilt refers to the angle formed between the lens plane and: