2024 ABO Exam Prep Part 5 - Multifocal Designs New Full Exam Questions and Answers ( Included ) 100% Correct
- This lens design is used for the correction of presbyopia & are needed to replace
plus power which has been lost to the crystalline lens
Answer: Bifocals
- The power of the bifocal segment that is always plus
Answer: Reading addition
- The power of this component is algebraically added to the power of the reading
addition to determine the total power
Answer: Spherical component of the carrier lens
- These 2 components remain unchanged when determining the total power
through a reading segment
Answer: Cylinder & axis
- The instant the eye enters the segment area, there is some base (down/up)
prism induced
Answer: Down
- This rule is applied to determine how much prism is induced in the segment area
Answer: Prentice's Rule
- The displacement of an image toward the apex of the prism when the eye enters
the segment area
Answer: Image jump
- Bifocal designs that reduces image jump, due to its round segment with the top cut
off
Answer: Flat top bifocal
- In bifocal designs, the optical center of the segment is located (clos-
er/farther) to the transition line, producing less image jump
Answer: Closer
- Multifocal lens design that contains no transition line & no image jump
Answer: - Progressive lenses
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- The temporal & nasal markings in progressive lens will be (mm) apart
Answer: 34 mm
- Frames for progressive lenses require this minimum range of vertical
measurement
Answer: 22-25 mm
- Recent "compact" progressive lens designs allow for this minimum verti- cal
measurement
Answer: 15 mm
- Areas of distortion on either side of the progressive channel
Answer: "Soft focus"
- This is located 2 to 4 mm above the MRP & below the DPZ in progressive lens
Answer: Fitting cross
16. DPZ
Answer: Distance power zone
- Area of the progressive lens found directly above the fitting cross
Answer: DPZ
- Area of the progressive lens located 2.5 mm inward from the MRP, averaging 10
to 16 mm below the MRP
Answer: Near zone
- Bifocal style designed so reading portion spans entire diameter of the lens; the OC
of the reading portion is located on/near the transition line
Answer: Franklin/Ex ecutive style
- Bifocal style that offers a large reading area with its OC of the reading portion
positioned at the bottom, resulting in excessive amounts of image jump
Answer: Ultex
- Bifocal style in which the reading segment is rounded & smoothed, how- ever
consists of 2-3 mm of unusable area
Answer: Blended
- Rounded segments range in size from (mm) in diameter
Answer: 22-28 mm
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