Dispensing Instrumentation Questions and Answers Flashcards
7 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 7 Dispensing Instrumentation Questions and Answers flashcards as text
When using a lensometer to verify a progressive addition lens, where should the distance power be confirmed?
Answer: In the upper portion of the lens through the distance corridor
The distance power of a progressive lens is verified through the upper distance zone of the lens on the lensometer.
Which instrument is used to measure the base curve of a finished spectacle lens?
Answer: Geneva lens clock (lens gauge)
The Geneva lens clock (lens gauge) measures the surface curvature, allowing the base curve of a spectacle lens to be determined.
A pupillometer is primarily used to measure:
Answer: The binocular and monocular pupillary distances
A pupillometer measures the distance between a patient's pupils, both binocularly and monocularly, to ensure accurate lens centration.
When neutralizing a lens with a lensometer, a spherical lens is confirmed when:
Answer: Both lines of the target are clear simultaneously at the same drum reading
A pure sphere shows both target lines simultaneously in sharp focus at one drum reading, confirming no cylinder power.
The distometer (or Rodenstock depth gauge) is used to measure:
Answer: Vertex distance between the back surface of the lens and the cornea
A distometer measures the vertex distance, the space between the back surface of the spectacle lens and the anterior corneal surface.
On a lensometer, the axis wheel is used to:
Answer: Align the cylinder axis of the lens being measured
The axis wheel rotates the target, allowing the dispenser to align the cylinder axis of the lens with the axis scale on the instrument.
Which frame adjustment tool applies heat to allow reshaping of plastic (zyl) frames?
Answer: Salt pan or frame warmer
A salt pan or frame warmer heats plastic frames so they become pliable and can be reshaped without cracking or breaking.