Unit 2 - Progressive Addition Lenses

Question 1

What does PAL stand for?

Answer 1

progressive addition lenses

Question 2

Conventional PALs obtain their increasing plus power toward the bottom of the lens by______.

a steeper F1 towards the bottom
a flatter F2 towards the bottom
a flatter F1 towards the bottom
a steeper F2 towards the top

Answer 2

a steeper F1 towards the bottom

Question 3

Conventional PALs are normally ground on the _____ surface of the lens blank.

front
middle
back
both

Answer 3

back

Question 4

Progressive addition lenses cannot be made from glass.
True
False

Answer 4

False

Question 5

The distance of a PAL is measured at the _______.

on the laser etching
in the distance circle
at the fitting cross
at the PRP

Answer 5

in the distance circle

Question 6

The near power of a PAL is measured at the ____.

a. fitting cross
b. near zone as a bifocal lens would be or read from the front surface laser print
c. distance circle
d. PRP

Answer 6

near zone as a bifocal lens would be or read from the front surface laser print

Question 7

Prism on a PAL is measured at the ______.

PRP
near zone
fitting cross
distance circle

Answer 7

PRP

Question 8

In a finished pair of specs with progressive lenses, where should the PD and ordered height be verified from?

The near OCs
the fitting crosses
the distance circles
the PRPs

Answer 8

the fitting crosses

Question 9

How many millimeters apart are the progressive “laser” markings?

32
28
34
38

Answer 9

34

Question 10

PALs will often be ground with equal amounts of BD prism for cosmetic purposes. What is this process called?

normal procedure
prism thinning
prism equalization
prism enhancement

Answer 10

prism thinning