ABO PRACTICAL
EXAM QUESTIONS
AND ANSWERS
Cancelling effect- subtract prism amounts - Answers -BU/BU
BD/BD
BI/BO
Powers between 0.00 & +/- 3.00 - Answers -Read in 1/8 diopters
.12
.37
.62
.87
Lensometer is also referred to as - Answers -Lensmeter, focimeter, vertometer
Where is the distance reference point (DRP) located on progressive lenses? - Answers
-generally located approximately 4 mm above the Fitting Point, providing an area
completely free of the progressive power gradient.
Near reference point (NRP) - Answers -represents the location on the surface that
provides the full target Add power, which is the optimal location for verifying the Add
power of the prescription. It is located at the center of the near checking circle ink
marking.
Major Reference Point: (MRP) - Answers -The point on a lens where the patient is
provided the prescription as written by the doctor. If prism is not called for in the
prescription then the lens OC and the MRP are the same.
Add power is - Answers -The difference between the sphere and power in reading area
of lens.
EXAM QUESTIONS
AND ANSWERS
Cancelling effect- subtract prism amounts - Answers -BU/BU
BD/BD
BI/BO
Powers between 0.00 & +/- 3.00 - Answers -Read in 1/8 diopters
.12
.37
.62
.87
Lensometer is also referred to as - Answers -Lensmeter, focimeter, vertometer
Where is the distance reference point (DRP) located on progressive lenses? - Answers
-generally located approximately 4 mm above the Fitting Point, providing an area
completely free of the progressive power gradient.
Near reference point (NRP) - Answers -represents the location on the surface that
provides the full target Add power, which is the optimal location for verifying the Add
power of the prescription. It is located at the center of the near checking circle ink
marking.
Major Reference Point: (MRP) - Answers -The point on a lens where the patient is
provided the prescription as written by the doctor. If prism is not called for in the
prescription then the lens OC and the MRP are the same.
Add power is - Answers -The difference between the sphere and power in reading area
of lens.
