optic zone diameter

(redirected from back optic zone diameter)

optic zone diameter 

Diameter of the optic zone (front or back) of a contact lens measured to the surrounding junction. It is commonly specified in millimetres. Specifically, there are the back optic zone diameter (BOZD), formerly called back central optic diameter (BCOD), and the front optic zone diameter (FOZD). It is often difficult to measure these dimensions due to the blending of the line separating the zones, especially for the back optic zone diameter. The region surrounding the central optic zone is the peripheral zone. If there is more than one, the zones will be numbered first, second, etc., beginning with the zone immediately surrounding the central optic zone. The diameter of each peripheral zone is referred to as the back (or front) peripheral zone diameter (BPZD). See blending; total diameter; edge lift.
References in periodicals archive ?
Back optic zone diameter BOZD 00 Back/front peripheral B/FPZD 01,2.
However, this remedy needs its own caution, as smaller diameter lenses often feel more uncomfortable, and will inevitably signify a smaller Back Optic Zone Diameter (BOZD), which may lead to concerns about flare
This measurement should be used as a guide to ensure the Back Optic Zone Diameter (BOZD) is greater than the largest pupil diameter.
a) Back optic zone radius (BOZR) and lens thickness b) Back optic zone radius (BOZR) and back optic zone diameter (BOZD) c) Back optic zone radius (BOZR) and back vertex power (BVP) d) Back optic zone diameter (BOZD) and lens thickness