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Note that some digital vendors will have their own rules for thicknesses, and they may over-ride the requested thickness from Rx-Universe.
IOT, Crossbows, and Essilor will respect MINEDG and MINCTR, and the resulting CTHICK is (usually) close to a requested center thickness. Zeiss appears to implement their own thickness constraints and the resulting CTHICK does not respect the requested MINCTR.
Electronic Interfaces
Rx-Universe can receive a specified center thickness as part of an order file sent in GIF format.
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