Originally Posted by
IaninIOM
Hi, I've just joined the board and realise that what I am about to say is to criticise existing members early in a relationship.
You have been given insufficient information to calculate both axial edge lift and axial thickness.
If you refer to : BS EN ISO 18369-1:2006+A1:2009 Ophthalmic Optics - Contact lens (Please note that it is an International Standard)
axial edge lift is defined as: distance between a point on the back of a contact lens at the edge and the vertex sphere, measured parallel to the contact lens axis.
So in your case Ocean you need to know the vertex sphere (BOZR which you have at 7.80mm) and the back peripheral zone radius at the Total Diameter (which apparently you have not been given).
I'm sorry if this has added to your confusion, if you order a rigid lens with a specified axial edge lift then when you view the fluorescein fit on the eye the edge lift is shown by the bright green ring around the edge of the lens, and tells by how much the lens is (hopefully) proud of the cornea at that point. Some GP lens types will specify the radial edge lift which the difference between the BOZR and BPZR. These two measuremnts can be confused but are in fact different especially in value.
If in doubt refer to the above ie ISO 18639-1:2006+A1:2009
Regards
Ian
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