this may be a stupid question, and I feel stupid for having to ask it, but here goes...
My lab techs were having some problens surfacing an Airwear aspheric transition lens. What was supposed to be a -0.50 sphere came out with about a half diopter of cylinder. They ran it twice. I love puzzles and have about ten plus years experience surfacing myself, so I looked at the work ticket and verified that rx was entered into rxcalc correctly, correct base curve was pulled, etc. So I aked if they laid out the lens on the cross. They told me that they never have and they just put a dot on the center of the cross engraved on the lens and disregard the actual "cross". I had no training documentation to pull for them regarding the use or reason for layout of the cross. I was always trained that the cross is there for a reason and to layout the lens with the cross at 0,180, and 90,270. you know like a cross. These guys insist that it makes no difference, yet when I ran the lens for them myself (using the blasted cross) the lens came out right.
So the question is, Am I right that the cross is there as a layout guide, and if so, where can I find documention to explain/prove the point to these techs?
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