Lens Defects - FINAL Flashcards
1
Q
bubbles in lenses are due to:
A
gas in batch
2
Q
stones in lenses are caused by:
A
foreign particles in batch
3
Q
a defect which presents as a crisscross pattern of cracks in the surface of the lens or coating
A
crazing
4
Q
polishing defect caused by incomplete or incorrect polishing
A
grayness
5
Q
thickness variation in application of scratch coatings
A
flow marks
6
Q
processing marks that just did not polish out
A
swirls
7
Q
to localize errors:
A
use high contrast grid with arc lamp
8
Q
errors are permissible if _
A
no measurable or gross lensometer target distortion or blur is found
9
Q
areas that are to be examined are within _ mm of DRP, excludes within 6mm of edge/progressive lenses are exempt
A
30
