ABO Practical Exam
Add power is - Correct Answer The difference between the sphere and power in reading area of lens.
*subtract full reading amount from sph. value
BD/BD - Correct Answer Cancels- subtract
BI/BI - Correct Answer Compounds- add
BI/BO - Correct Answer Cancels- subtract
Binocular PD - Correct Answer Total PD of both eyes together. From one pupil to the other pupil.
Black numbers on lensometer power drum - Correct Answer (+)
BO/BO - Correct Answer Compounds- add
BU/BD - Correct Answer Compounds- add
BU/BU - Correct Answer Cancels- subtract
Cancelling effect- subtract prism amounts - Correct Answer BU/BU
BD/BD
BI/BO
Cylinder power is always used to determine if axis - Correct Answer Meets ANSI standards
Fill in all parts of the reading values found in the correct form, including all: - Correct Answer Zeros
Ex. X 090
+0.50
Focus sphere lines first, if cylinder lines focus first - Correct Answer Rotate axis drum by 90°
How to check for vertical imbalance - Correct Answer 1) mark OD, OC by centering within retical
2) without moving the lens table, move to OS lens
3) if not still centered, there is imbalance.
Lensometer is also referred to as - Correct Answer Lensmeter, focimeter, vertometer
Major Reference Point: (MRP) - Correct Answer 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.
Measure cylinder value of the lens by: bringing far lines into focus, THEN: - Correct Answer Subtract current
measurement on power drum from spherical reading.
Monocular PD - Correct Answer Individual PD of each eye. From pupil to bridge.
Near reference point (NRP) - Correct Answer 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.
Optical Infinity - Correct Answer used to measure distance PD-is a distance of about twenty feet.
P=hcmxd - Correct Answer Prentice rule
P(prism)
Hcm(amount moved)
Add power is - Correct Answer The difference between the sphere and power in reading area of lens.
*subtract full reading amount from sph. value
BD/BD - Correct Answer Cancels- subtract
BI/BI - Correct Answer Compounds- add
BI/BO - Correct Answer Cancels- subtract
Binocular PD - Correct Answer Total PD of both eyes together. From one pupil to the other pupil.
Black numbers on lensometer power drum - Correct Answer (+)
BO/BO - Correct Answer Compounds- add
BU/BD - Correct Answer Compounds- add
BU/BU - Correct Answer Cancels- subtract
Cancelling effect- subtract prism amounts - Correct Answer BU/BU
BD/BD
BI/BO
Cylinder power is always used to determine if axis - Correct Answer Meets ANSI standards
Fill in all parts of the reading values found in the correct form, including all: - Correct Answer Zeros
Ex. X 090
+0.50
Focus sphere lines first, if cylinder lines focus first - Correct Answer Rotate axis drum by 90°
How to check for vertical imbalance - Correct Answer 1) mark OD, OC by centering within retical
2) without moving the lens table, move to OS lens
3) if not still centered, there is imbalance.
Lensometer is also referred to as - Correct Answer Lensmeter, focimeter, vertometer
Major Reference Point: (MRP) - Correct Answer 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.
Measure cylinder value of the lens by: bringing far lines into focus, THEN: - Correct Answer Subtract current
measurement on power drum from spherical reading.
Monocular PD - Correct Answer Individual PD of each eye. From pupil to bridge.
Near reference point (NRP) - Correct Answer 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.
Optical Infinity - Correct Answer used to measure distance PD-is a distance of about twenty feet.
P=hcmxd - Correct Answer Prentice rule
P(prism)
Hcm(amount moved)
