ABO NOCE Basic Opticianry ABO NOCE MCQ 3 — Questions and Answers
Question 1: What is the index of refraction of crown glass?
- 1.523 (Correct answer)
- 1.586
- 1.499
- 1.700
Correct answer: 1.523
Standard crown glass has an index of refraction of approximately 1.523, which is the baseline for most optical calculations.
Question 2: Which prism orientation would correct a right hyperphoria?
- Base down before the right eye (Correct answer)
- Base up before the right eye
- Base in before the right eye
- Base out before the right eye
Correct answer: Base down before the right eye
Right hyperphoria means the right eye deviates upward, so base-down prism before the right eye redirects the image downward to compensate.
Question 3: What is the primary purpose of the distance between lenses (DBL) measurement?
- To determine the width of the bridge (Correct answer)
- To calculate the total frame width
- To measure pantoscopic tilt
- To determine lens thickness
Correct answer: To determine the width of the bridge
DBL (distance between lenses) measures the width of the bridge, which determines how the frame fits across the nose.
Question 4: A prescription of -4.00 DS is ordered in polycarbonate. What is the primary advantage of polycarbonate for this prescription?
- Impact resistance (Correct answer)
- Higher Abbe value
- Better scratch resistance
- Lower cost
Correct answer: Impact resistance
Polycarbonate's primary advantage is its exceptional impact resistance, making it the preferred safety material regardless of prescription power.
Question 5: What does 'vertex distance' refer to?
- The distance from the back surface of the lens to the cornea (Correct answer)
- The distance between the two lenses
- The depth of the frame eye wire
- The distance from the bridge to the temple
Correct answer: The distance from the back surface of the lens to the cornea
Vertex distance is the measurement from the back surface (ocular side) of a spectacle lens to the anterior surface of the cornea.
Question 6: Transposition of +1.50 -3.00 x 045 to minus cylinder form yields which result?
- -1.50 +3.00 x 135 (Correct answer)
- -1.50 -3.00 x 135
- +1.50 +3.00 x 045
- -1.50 +3.00 x 045
Correct answer: -1.50 +3.00 x 135
To transpose: new sphere = algebraic sum (+1.50 + (-3.00) = -1.50), new cylinder = opposite sign (+3.00), new axis = 90° away (045+90=135).
Question 7: Which lens tint color is most appropriate for enhancing contrast on a snow-covered ski slope?
- Yellow or amber (Correct answer)
- Green
- Blue
- Gray
Correct answer: Yellow or amber
Yellow and amber tints enhance contrast in flat-light conditions by filtering blue light and improving depth perception on snow.
ABO NOCE Basic Opticianry ABO NOCE MCQ 3
What is the index of refraction of crown glass?