ABO NOCE Basic Opticianry ABO NOCE MCQ 5 — Questions and Answers
Question 1: A frame with a 'wrap' style has a face form angle of 15 degrees. How does this affect the effective power of a prescription lens?
- It induces unwanted cylinder and changes the effective sphere power (Correct answer)
- It only affects the cosmetic appearance of the lens
- It increases the prismatic effect at the optical center
- It decreases the vertex distance only
Correct answer: It induces unwanted cylinder and changes the effective sphere power
Face form (pantoscopic tilt and wrap angle) causes off-axis viewing through the lens, inducing unwanted oblique astigmatism that must be compensated in the prescription.
Question 2: Which of the following is NOT a required element on a valid eyeglass prescription under FTC rules?
- The patient's insurance information (Correct answer)
- Expiration date
- Prescriber's signature
- Issue date
Correct answer: The patient's insurance information
The FTC Eyeglass Rule requires the patient's name, issue date, expiration date, and prescriber signature/address — insurance information is not required.
Question 3: What is the purpose of pantoscopic tilt in frame fitting?
- To align the optical axis of the lens with the patient's visual axis for near gaze (Correct answer)
- To increase the cosmetic appeal of the frame
- To reduce the vertex distance
- To increase the effective base curve
Correct answer: To align the optical axis of the lens with the patient's visual axis for near gaze
Pantoscopic tilt (typically 8-12°) angles the bottom of the lens toward the face so the optical axis aligns with the visual axis during downward near-vision gaze.
Question 4: A lens has a base curve of 6.00 D and a back curve of -4.00 D. What is the approximate refractive power of the lens?
- +2.00 D (Correct answer)
- +10.00 D
- -2.00 D
- +4.00 D
Correct answer: +2.00 D
Lens power ≈ front curve + back curve = +6.00 + (-4.00) = +2.00 D, using the lensmaker's principle for thin lenses.
Question 5: When should an optician recommend polycarbonate lenses without exception?
- For all children's eyewear and monocular patients (Correct answer)
- For all patients with prescriptions over -4.00 D
- For all patients requesting photochromic lenses
- For all patients who drive frequently
Correct answer: For all children's eyewear and monocular patients
Polycarbonate is mandated for children and monocular patients due to its superior impact resistance, protecting the one functional eye or developing eyes from injury.
Question 6: What is the purpose of the segment height measurement in a bifocal or progressive lens fitting?
- To position the near or reading zone at the correct height for the patient's gaze (Correct answer)
- To determine the width of the reading segment
- To calculate the minimum blank size
- To set the pantoscopic tilt angle
Correct answer: To position the near or reading zone at the correct height for the patient's gaze
Segment height determines the vertical placement of the reading zone (bifocal seg top or progressive corridor start) relative to the pupil or lower lid.
Question 7: A patient has a prescription of -6.00 D. Which lens material would produce the thinnest lens?
- High-index 1.74 (Correct answer)
- Polycarbonate 1.586
- CR-39 1.499
- Crown glass 1.523
Correct answer: High-index 1.74
Higher refractive index materials bend light more efficiently, requiring less lens material to achieve the same power — 1.74 index produces the thinnest lens.
ABO NOCE Basic Opticianry ABO NOCE MCQ 5
A frame with a 'wrap' style has a face form angle of 15 degrees.
How does this affect the effective power of a prescription lens?