Ch. 5: Reference Point Placement,
Multifocal Height, & Blank Size
Determination Exam Questions All
Answered Correct.
Adjust the nosepads - Answer When taking OC or seg height measurements on a metal frame,
the dispenser must _____________________________ first.
At the optical center - Answer For SV lenses with no prism, where is the MRP?
Prismatic effect - Answer If the OC's aren't lined up with a patient's pupils, it will induce:
At the point where the correct prism is induced. - Answer For glasses with prescribed prism,
where is the MRP?
Improves frame appearance
Aligns both lens surfaces with pt's line of sight - Answer 2 advantages of face-form in glasses?
No face-form - Answer If the wearer's PD is equal to the frame PD, what is the face-form
recommendation?
Give the frame face-form by bending at the bridge - Answer If the wearer's PD is less than the
frame PD, what is the face-form recommendation?
Leave the frame with no face-form. (Theoretically, "negative" face-form is called for, but this is
impractical.) - Answer If the wearer's PD is greater than the frame PD, what is the face-form
recommendation?
Unwanted sphere & cyl powers - Answer If the wearer's PD is less than the frame PD and no
face-form is given, what will result?
Centered vertically in the frame - Answer Unless specified, where does the lab put the MRP
vertically?
, High-powered & aspheric - Answer ___________________ lenses should always have an MRP
height specified.
Unwanted sphere & cyl - Answer If a lens is tilted with the OC aligned with the pupil, it will
induce:
Higher - Answer In most cases, the pupil sits slightly _______________ than the geometric
center of the lens.
OC is lowered 1 mm for every 2 degrees of pantoscopic tilt - Answer What is the general rule
for adjusting OC heights for pantoscopic tilt?
Chromatic aberration - Answer With high-powered and aspheric lenses, the farther from the
OC the eye looks, the more _________________________.
Aberration due to lens tilt
Thicker lenses - Answer Some dispensers do not lower the MRP to compensate for
pantoscopic tilt. This can result in:
Top of the lens gets thinner
Bottom of the lens gets thicker - Answer Raising the OC of a minus lens results in:
Top of the lens gets thicker
Sometimes increases center thickness - Answer Raising the OC of a plus lens can result in:
Lens thickness - Answer When ordering high-powered lenses with high OC's, it is important to
consider:
Polycarbonate lenses
High-index lenses
Aspheric lenses - Answer MRP height should be measured for what lens types?
Horizontal midline - Answer You should never move the MRP height below the
__________________________ unless the lenses are exclusively for near work.
Multifocal Height, & Blank Size
Determination Exam Questions All
Answered Correct.
Adjust the nosepads - Answer When taking OC or seg height measurements on a metal frame,
the dispenser must _____________________________ first.
At the optical center - Answer For SV lenses with no prism, where is the MRP?
Prismatic effect - Answer If the OC's aren't lined up with a patient's pupils, it will induce:
At the point where the correct prism is induced. - Answer For glasses with prescribed prism,
where is the MRP?
Improves frame appearance
Aligns both lens surfaces with pt's line of sight - Answer 2 advantages of face-form in glasses?
No face-form - Answer If the wearer's PD is equal to the frame PD, what is the face-form
recommendation?
Give the frame face-form by bending at the bridge - Answer If the wearer's PD is less than the
frame PD, what is the face-form recommendation?
Leave the frame with no face-form. (Theoretically, "negative" face-form is called for, but this is
impractical.) - Answer If the wearer's PD is greater than the frame PD, what is the face-form
recommendation?
Unwanted sphere & cyl powers - Answer If the wearer's PD is less than the frame PD and no
face-form is given, what will result?
Centered vertically in the frame - Answer Unless specified, where does the lab put the MRP
vertically?
, High-powered & aspheric - Answer ___________________ lenses should always have an MRP
height specified.
Unwanted sphere & cyl - Answer If a lens is tilted with the OC aligned with the pupil, it will
induce:
Higher - Answer In most cases, the pupil sits slightly _______________ than the geometric
center of the lens.
OC is lowered 1 mm for every 2 degrees of pantoscopic tilt - Answer What is the general rule
for adjusting OC heights for pantoscopic tilt?
Chromatic aberration - Answer With high-powered and aspheric lenses, the farther from the
OC the eye looks, the more _________________________.
Aberration due to lens tilt
Thicker lenses - Answer Some dispensers do not lower the MRP to compensate for
pantoscopic tilt. This can result in:
Top of the lens gets thinner
Bottom of the lens gets thicker - Answer Raising the OC of a minus lens results in:
Top of the lens gets thicker
Sometimes increases center thickness - Answer Raising the OC of a plus lens can result in:
Lens thickness - Answer When ordering high-powered lenses with high OC's, it is important to
consider:
Polycarbonate lenses
High-index lenses
Aspheric lenses - Answer MRP height should be measured for what lens types?
Horizontal midline - Answer You should never move the MRP height below the
__________________________ unless the lenses are exclusively for near work.
