back vertex power

back ver·tex pow·'er

the effective power of a lens as measured from a surface toward the eye; a standard for measurement of ophthalmic lenses.
References in periodicals archive ?
However, only a small subset of the ISO specified lens design parameters are typically utilised by practitioners to specify a contact lens: back optic zone radius (BOZR), usually referred to as base curve on lens packaging, total diameter (TD), and back vertex power (BVP).
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
They can be manufactured to a large range of back vertex powers (+/-40.