Prescription AnalysisQuestion 51 of 100
Compensated power calculations are most critical when the fitted vertex distance differs from what?
a.The frame PD
b.The refracted vertex distance
c.The seg height
d.The base curve
Explanation
The refraction is done at a specific vertex distance; when the dispensed frame sits at a different vertex distance, the effective power shifts, so compensation restores the intended power at the eye.
Practice all 100 questions free — no signup required.
Related questions on this topic
- A patient needs 3 prism diopters base down in the right lens. If the lens is +2.00 D, how much decentration achieves this (Prentice's rule)?
- Slab-off prism is used to correct what condition in a multifocal wearer?
- The written Rx 'OU' means what?
- A spherical equivalent of the Rx -2.00 -1.00 x 180 is what?
- When both eyes require decentration for a smaller PD than the frame, the optical centers are moved which way?
- Reading an Rx that lists 'BO' after a prism value indicates the base is oriented how?
Last reviewed: · editorial process
PrepPass Editorial Team · Verified against ABO (American Board of Opticianry) Certified Optician Exam · How we review