back optic zone radius

optic zone radius, back (BOZR) 

Radius of curvature of the back optic zone of a contact lens. (It was formerly called the back central optic radius (BCOR or BC) or posterior central curve radius (PCCR).) If the optic zone is surrounded by a peripheral zone there will be a radius of curvature of a back peripheral zone (BPR). If there are several zones there will be BPR₁, BPR₂, etc., beginning with the zone immediately surrounding the central optic zone. See Drysdale's method; radiuscope; Toposcope.

Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann