Presbyopia and Multifocals

Question 1

The ability of the eye to variably focus is known as what?

Answer 1

Accommodation

Question 2

Which structure of the eye provides it with variable focusing capability?

Answer 2

Crystalline lens

Question 3

How much accommodative ability does the average person have at birth?

Answer 3

15.00 D

Question 4

What is the definition of presbyopia?

Answer 4

The inability to see near objects clearly and comfortably

Question 5

As a person ages, their near point does what?

Answer 5

Recedes

Question 6

What percentage of the US population was estimated to become presbyopic by the year 2020?

Answer 6

42%

Question 7

According to US Census data projected to 2050, which is the only age group that will show an increase in number?

Answer 7

55+

Question 8

What percentage of the current US population over 55 needs eyewear?

Answer 8

84%

Question 9

As a practicing optician, your role with presbyopic patients will be to determine their lifestyle needs and wants in order to do what?

Answer 9

Match product features and benefits to them

Question 10

What was the earliest form of presbyopic lens correction?

Answer 10

Single vision lenses - readers

Question 11

Who is attributed with the concept of correcting presbyopia with bifocals?

Answer 11

Benjamin Franklin

Question 12

What was the design of the first bifocal lens?

Answer 12

Two differently powered halves secured in the same eyewire

Question 13

What was a problem that was not associated with August Morck’s cemented bifocal lenses?

Answer 13

The different indices between the distance lens and the wafer lens caused color aberration for the wearer

Question 14

What was the name of the glass bifocal lens design that was the first to use a fusing process?

Answer 14

The Kryptok

Question 15

Which bifocal lens exhibited color aberration for the wearer through the segment?

Answer 15

Kryptok

Question 16

When was the first trifocal lens developed?

Answer 16

1936

Question 17

What is the furthest and closest a person will be able to see if he is looking through a plano distance, +2.50 add multifocal and has 4.00D of accommodative amplitude?

Answer 17

40cm to 15.4cm

Question 18

For a specified distance rx power, what happens to the ranges of clear vision through a segmented multifocal as add powers get high?

Answer 18

The zones shrink

Question 19

What is a significant indication of the “Ranges of Clear Vision Through Multifocals” chart?

Answer 19

Fixed power zone segmented lenses may not be the best way to correct presbyopia

Question 20

Why did progressives take so long to enter the marketplace from the time they were first theorized?

Answer 20

The technology needed to produce them was not available

Question 21

The blended region between the distance and near zones of a progressive addition is known as the _____ zone.

Answer 21

Intermediate

Question 22

When a lens has its surface astigmatism concentrated into smaller areas of the lens, it is classified as _____ design

Answer 22

hard

Question 23

Which progressive lens design classification do most manufacturers use?

Answer 23

A combination of hard and soft

Question 24

Who designed the first progressive addition lens?

Answer 24

Bernard Maitenaz

Question 25

How did the original Varilux lens use aspheric power?

Answer 25

It used all its progressive power in 12mm

Question 26

How did the Varilux II lens use aspheric power?

Answer 26

The lens was completely progressive from top to bottom

Question 27

Which progressive addition lens was the first to employ true right and left blanks?

Answer 27

Varilux

Question 28

What is the advantage of using multi-design for progressive addition lenses?

Answer 28

The lens design changes as add power increases based on the intended needs of the wearer as they age

Question 29

Define asymmetrical design in progressive lenses

Answer 29

There is more surface astigmatism in one side of the lens than then other and/or the areas of surface astigmatism are not equal

Question 30

What is the advantage of a short corridor progressive lens design?

Answer 30

It allows the use of a shallow B measurement frame

Question 31

What is the best method for assessing the potential success of a progressive addition lens?

Answer 31

Wearer trials

Question 32

All early progressive addition lenses were designed for what?

Answer 32

General use

Question 33

What is the name of the software files used by direct-to-surface (free-form) generators?

Answer 33

Point files

Question 34

Why should you have the lens markings on a progressive lens at the time of delivery adjustment?

Answer 34

So you can accurately align the fitting cross with the pupil center