Patient Measurement

Question 1

What is the Boxing System used for?

Answer 1

It enables us to record the exact size to which that shape should be duplicated by visualizing each shape in a box

Question 2

What is the “A” Measurement?

Answer 2

also known as frame size, it’s the horizontal frame measurement

Question 3

What is the “DBL” measurement?

Answer 3

distance between lenses, also known as bridge size

Question 4

What is the “ED” measurement?

Answer 4

the Effective diameter. the longest point across

Question 5

What is the “B” measurement?

Answer 5

The vertical measurement

Question 6

What is the “GC” measurement?

Answer 6

The Geometric Center of the frame

Question 7

How can you measure the GC?

Answer 7

Taking half of the “A” Measurement and half of the “B” measurement written as coordinates. Ex. 25x16

Question 8

What is the “DBC” measurement?

Answer 8

Distance between Centers, also known as Frame PD

Question 9

How do you measure DBC?

Answer 9

“A” measurement plus “DBL” measurement

Question 10

How can you use the boxing system if you don’t have any lenses?

Answer 10

Use the frame instead and measure from the inside of the frame, including the interior groove.

Question 11

How do you measure Seg Vertical Decentration?

Answer 11

1/2 “B” measurement minus the Seg height

Question 12

When measuring a seg height for a Bifocal lens, where do you measure from?

Answer 12

Lower edge of lid

Question 13

When measuring a seg height for a Trifocal lens, where do you measure from?

Answer 13

Lower edge of pupil

Question 14

When measuring seg heights, do you use the PD, GC, or deepest point of the lens?

Answer 14

The deepest part of the lens

Question 15

For progressives, where is the best place to measure the seg?

Answer 15

mid pupil

Question 16

What is the range of recommended fitting heights for Progressives?

Answer 16

22-24 mm

Question 17

When measuring seg heights, should you do it before or after adjusting the frame on the patient?

Answer 17

after

Question 18

What are the advantages to taking Monocular PD’s?

Answer 18

1. It’s the most commonly used measurement.
2. It takes PD individually and will be more accurate to the patients Rx

Question 19

On what common occasions would you measure Binocular PD’s?

Answer 19

For Lined Bifocals and trifocals

Question 20

What is the standard difference in PD measurement between a persons Far PD and their Near PD?

Answer 20

Near is generally 3mm less then Far when measuring Binocularly

Question 21

Explain how to do measure binocular PD using PD Rule

Answer 21

1. Start by positioning yourself 16 inches from Patient.
2. Place ruler on their bridge
3. Close your right eye and tell patient to look at your open left eye, center the zero mark in center of their right pupil.
4. Close your left eye and tell patient to look at your open right eye, line the other side of your ruler to the center of their left pupil and check the number on the Ruler

Question 22

What does a Lens Clock/Base Curve reader do?

Answer 22

Reads the dioptric curvatures of a lens surface

Question 23

When are the black numbers and the red numbers used on a Lens Clock?

Answer 23

Black numbers are used when checking the FRONT surface of a lens, and the Red numbers are used when checking the BACK surface of a lens.