Unit 1 - Multi-Focal Lenses

Question 1

The intersection of the horizontal and vertical lines on the blocker layout grid represent:

PRP
Frame GC
MC
Lens OC

Answer 1

Frame GC

Question 2

In the Trifocal design referred to as a 7 x 28 (pronounced “ seven by twenty-eight), what does the seven represent?

the date of manufacture
the width of the segment
the depth of the near zone
the depth of the intermediate zone

Answer 2

the depth of the intermediate zone

Question 3

A layout blocker has which of the following?

A segment aligning guide
Axis reference lines
A mechanical center
No segment aligning guide

Answer 3

a segment aligning guide

Question 4

Layout blockers decenter right lenses “in”

To the right
To the concave side
To the left
To the temporal side

Answer 4

to the right

Question 5

On a lens blank, bifocal lens segment "inset" is referenced from the
  Bridge of the frame 
  The "A" measurement 
  Nasal edge to the temporal edge 
  Distance PRP to the near OC

Answer 5

Distance PRP to the near OC

Question 6

Flat top trifocal lenses are decentered horizontally and vertically in the same manner as:

Progressive lenses
Bifocal lenses
All lenses
Single vision lenses

Answer 6

bifocal lenses

Question 7

The reference point on a lens for flat top lens vertical decentration is:

Segment top
Near OC
Lens edge
Distance MRP

Answer 7

segment top

Question 8

Normal multifocal decentration can include all of the following except:

“Out” decentration
Horizontal decentration
Decentration for prism
Vertical decentration

Answer 8

decentration for prism

Question 9

The position of the PRP to the Near OC is equal to the patient’s:

Near PD
Distance PD
Amount of convergence
Fitting Height

Answer 9

amount of convergence

Question 10

The most common Bifocal design sold in the U.S. today is the_____________.

Flat Top 28
Flat Top 35
Round 22
Ultex

Answer 10

flat top 28