peter lec Flashcards

(13 cards)

1
Q

What are bifocals used for

A

Correction of presbyopia and are needed to replace plus power

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Who developed Bifocals

A

Ben Franklin in 1784

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are Stock lenses

A

lenses that are finished and referred to uncuts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what do Progressive lenses have

A

Have a corridor and intermediate vision and a fitting cross

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

the fitting cross is usually how many mm from the corridor

A

4mm above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What markings do Progressive lens have

A

Distance verification circle, near verification circle, fitting cross, prism reference point, Datum line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where are progressives usually measured

A

At the mid-pupil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Progressive lens verification have

A

Manufacturers engrave brand icons and add power usually on the nasal side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do you find distance decentration

A

FPD-DPD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do you find inset

A

DPD-NPD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do you find the below measurement

A

half of B and subtract by height and you get your below

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How do you find total decentration

A

DPD+Inset

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly