Hello Boys.
Some our customers (..opticians) , sometimes ,send me some edged lenses to check their defective surface coating (A.R., A.S.) .
Not Always, but often , i found big A.R. cracks , due to a deformation of the lens (i mean a gain of 2 , 3 front diopters).
When i try to explain that, obviously , the origin of the problem can be a trouble of compatibility from the frame curve and the lens front curve , their answer is that a good tolerance between this two curve rays must be 'normal'. So the lenses are defective! .
:drop:
I would like to know your opinions , because i'm confused:hammer:
The lenses are negative cr 39 stock lenses and the frame material in most cases is tri-acetate(in very few cases the material is metal).
Mauro
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