11/26/25, 3:59 PM ABO Practical Exam study guide COMPLETE EXAM Questions and Answers (Verified Answers) (Latest Update 2025) UPDATE!! …
ABO Practical Exam study guide COMPLETE
EXAM Questions and Answers (Verified Answers)
(Latest Update 2025) UPDATE!!
Save
Terms in this set (85)
Single Vision corrects for one distance
Multifocal Corrects with two or more prescriptions (or 'powers')
Bifocal lens having two focus strengths
Trifocal pertaining to having three focus strengths
obtained at the center of an optical lens by producing
a difference in edge thickness, either by grinding the
Calculating Prismatic
back surface at an angle to the front surface during
Effects
lens surfacing or, if the lens has sufficient power, de-
centering the optical center of the lens
BI & BI
Compounding Prism BO & BO
BU & BD
BI & BO
Cancelling Prism BD & BD
BU & BU
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, 11/26/25, 3:59 PM ABO Practical Exam study guide COMPLETE EXAM Questions and Answers (Verified Answers) (Latest Update 2025) UPDATE!! …
P=hcm x D
P=amount of prism created
Prentice's Rule h= number of cm OC moved
cm= centimeters (convert to mm, divide by 10)
D= power in meridian with error
The difference in vertical prism power at the reading
Vertical Imbalance
level in a pair of lenses.
SV = 1/2 of B
OC Height's by lens Progressive = Fitting cross
FT = 5mm above segment
A plus lens when moved farther from the eye gains in
Vertex Compensation plus power
Distance is 0 with CL because they are on the eye
De= Dl/(1 + d xDl)
De= diopter effective value of error created
D/= lens power (given power)
Vertex compensation
d= amount in METERS lens moved from refracted
Formula
position to position lens is worn
Keep sign for what it is (+/-)
- to d means moves away
Horizontal Centration PD
Vertical Centration OC
Horizontal & Vertical Given PD/OC - Human PD/OC= mm moved
Centration Formula Frame PD is found by adding A+DBL
Dt= (sina)²x Dc +Ds
Dt= Total Power we need
Power in Oblique
(sina)²= degree we have degree we need
Meridians
Dc= cylinder power
Ds= sphere power
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ABO Practical Exam study guide COMPLETE
EXAM Questions and Answers (Verified Answers)
(Latest Update 2025) UPDATE!!
Save
Terms in this set (85)
Single Vision corrects for one distance
Multifocal Corrects with two or more prescriptions (or 'powers')
Bifocal lens having two focus strengths
Trifocal pertaining to having three focus strengths
obtained at the center of an optical lens by producing
a difference in edge thickness, either by grinding the
Calculating Prismatic
back surface at an angle to the front surface during
Effects
lens surfacing or, if the lens has sufficient power, de-
centering the optical center of the lens
BI & BI
Compounding Prism BO & BO
BU & BD
BI & BO
Cancelling Prism BD & BD
BU & BU
https://quizlet.com/1113585542/abo-practical-exam-study-guide-complete-exam-questions-and-answers-verified-answers-latest-update-2025-update-fl… 1/9
, 11/26/25, 3:59 PM ABO Practical Exam study guide COMPLETE EXAM Questions and Answers (Verified Answers) (Latest Update 2025) UPDATE!! …
P=hcm x D
P=amount of prism created
Prentice's Rule h= number of cm OC moved
cm= centimeters (convert to mm, divide by 10)
D= power in meridian with error
The difference in vertical prism power at the reading
Vertical Imbalance
level in a pair of lenses.
SV = 1/2 of B
OC Height's by lens Progressive = Fitting cross
FT = 5mm above segment
A plus lens when moved farther from the eye gains in
Vertex Compensation plus power
Distance is 0 with CL because they are on the eye
De= Dl/(1 + d xDl)
De= diopter effective value of error created
D/= lens power (given power)
Vertex compensation
d= amount in METERS lens moved from refracted
Formula
position to position lens is worn
Keep sign for what it is (+/-)
- to d means moves away
Horizontal Centration PD
Vertical Centration OC
Horizontal & Vertical Given PD/OC - Human PD/OC= mm moved
Centration Formula Frame PD is found by adding A+DBL
Dt= (sina)²x Dc +Ds
Dt= Total Power we need
Power in Oblique
(sina)²= degree we have degree we need
Meridians
Dc= cylinder power
Ds= sphere power
https://quizlet.com/1113585542/abo-practical-exam-study-guide-complete-exam-questions-and-answers-verified-answers-latest-update-2025-update-fl… 2/9
