Lesson 12 Flashcards
Why are multifocal lenses the best solution for presbyopia
The add gives close vision and the rest allows for distance viewing
What’s the distance from the top of the full lens to the top of the segment
Segment drop
What’s the distance from the top of segment to the bottom of the carrier lens
Segment height
What’s the distance of the segment
Segment depth
Describe the stronger and weaker effective self of the plus lens:
Stronger effective: vertex distance increased
Weaker effective: vertex distance decreased
Describe the stronger and weaker effective self of the minus lens:
Stronger effective: vertex distance decreased
Weaker effective: vertex distance increased
What is compensated power
New power that the new lens will need have in order to have the same effective power as original lens when placed in new vertex distance
A flat top is also known as
A half moon, straight top, D segment
What are the cons of progressive lenses
There is a distortion at the outer parts of the lens and they give headaches and dizzy spells
What are compact progressive designs
Style in which there is a shorter transition zone between distance and near powers
How are the central part and the reading areas of compact progressive designs
They are effectively larger
