What exactly does the lab caculate to incorporate a balanced lens ?:cheers:
What exactly does the lab caculate to incorporate a balanced lens ?:cheers:
:)
It depends on which lab and its policies and the dispenser. Some labs do a balance lens as half power of the other, some duplicate power. I like to duplicate when possible to match magni/mini-fication and weight. Hopefully some of our more knowledgeable lab folk will chime in.
I like to dup the other eye and I try to place the axis in a mirror position when I make the lens so the thickness looks symetrical.
For example
-1.00 -2.00 x 045
Balance (-1.00 -2.00 x 0135)
The jobs come out looking nicer.
1st* HTML5 Tracer Software
1st Mac Compatible Tracer Software
1st Linux Compatible Tracer Software
*Dave at OptiVision has a web based tracer integration package that's awesome.
We will match powers (Sph. and Cyl.)and use opposite axis on oblique cylinder powers to make it as symetrical as possible. For example if a lens with a 2 cyl. has an axis of 65 we will enter an axis of 115 for the balance lens. This really is only necessary with cylinder powers of any significance. We also give a courtesy discount on the lens that is the balance.
Hope that helps.
Hey guys;
Thanks for the mention of the axis shifts, I failed to mention it, but do recommend when powers dictate.
We also try to use a reciprocal axis to balance the thickness and the cosmetic appearance of the eye. We recently did this in reverse. We used a balance lens with high cyl to bring the appearance of a disfigured eye to look more natural. The patient and her family were astonished, and wondered why no one had bothered to do it for her before. (just one of those little things a real optician can do for you.)
Many thanks for all the answers. Its a real help.:)
:)
Every balance lens I've seen from my lab when we just ask for "balance" is the sphere power of the other lens.
Example:
R. Balance (-5.00)
L -5.00 -1.00 x130
i use the same Rx in the balance eye, just reverse the axis.
it gives a good balance the eyewear and the patient seems to be happier with the symetry.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Bookmarks