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ABO-NCLE PRACTICAL EXAM QUESTION BANK LATEST
2024-2025 COMPLETE 250 QUESTIONS AND CORRECT
DETAILED SOLUTIONS JUST RELEASED
ABO-NCLE PRACTICAL VERSION 1
Single Vision - CORRECT ANSWER✔✔corrects for one distance
Multifocal - CORRECT ANSWER✔✔Corrects with two or more prescriptions (or
'powers')
Bifocal - CORRECT ANSWER✔✔lens having two focus strengths
Trifocal - CORRECT ANSWER✔✔pertaining to having three focus strengths
Calculating Prismatic Effects - CORRECT ANSWER✔✔obtained at the center of an
optical lens by producing a difference in edge thickness, either by grinding the
back surface at an angle to the front surface during lens surfacing or, if the lens
has sufficient power, de-centering the optical center of the lens
1
SUCCESS!
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Compounding Prism - CORRECT ANSWER✔✔BI & BI
BO & BO
BU & BD
Cancelling Prism - CORRECT ANSWER✔✔BI & BO
BD & BD
BU & BU
Prentice's Rule - CORRECT ANSWER✔✔P=hcm x D
P=amount of prism created
h= number of cm OC moved
cm= centimeters (convert to mm, divide by 10)
D= power in meridian with error
Vertical Imbalance - CORRECT ANSWER✔✔The difference in vertical prism power
at the reading level in a pair of lenses.
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SUCCESS!
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OC Height's by lens - CORRECT ANSWER✔✔SV = 1/2 of B
Progressive = Fitting cross
FT = 5mm above segment
Vertex Compensation - CORRECT ANSWER✔✔A plus lens when moved farther
from the eye gains in plus power
Distance is 0 with CL because they are on the eye
Vertex compensation Formula - CORRECT ANSWER✔✔De= Dl/(1 + d xDl)
De= diopter effective value of error created
D/= lens power (given power)
d= amount in METERS lens moved from refracted position to position lens is worn
Keep sign for what it is (+/-)
- to d means moves away
Horizontal Centration - CORRECT ANSWER✔✔PD
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SUCCESS!
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Vertical Centration - CORRECT ANSWER✔✔OC
Horizontal & Vertical Centration Formula - CORRECT ANSWER✔✔Given PD/OC -
Human PD/OC= mm moved
Frame PD is found by adding A+DBL
Power in Oblique Meridians - CORRECT ANSWER✔✔Dt= (sina)²x Dc +Ds
Dt= Total Power we need
(sina)²= degree we have degree we need
Dc= cylinder power
Ds= sphere power
Lensmeter - CORRECT ANSWER✔✔is an ophthalmic instrument. It is mainly used
by optometrists and opticians to verify the correct prescription in a pair of
eyeglasses, to properly orient and mark uncut lenses, and to confirm the correct
mounting of lenses in spectacle frames. (also known as a focimeter or vertometer)
4
SUCCESS!
ABO-NCLE PRACTICAL EXAM QUESTION BANK LATEST
2024-2025 COMPLETE 250 QUESTIONS AND CORRECT
DETAILED SOLUTIONS JUST RELEASED
ABO-NCLE PRACTICAL VERSION 1
Single Vision - CORRECT ANSWER✔✔corrects for one distance
Multifocal - CORRECT ANSWER✔✔Corrects with two or more prescriptions (or
'powers')
Bifocal - CORRECT ANSWER✔✔lens having two focus strengths
Trifocal - CORRECT ANSWER✔✔pertaining to having three focus strengths
Calculating Prismatic Effects - CORRECT ANSWER✔✔obtained at the center of an
optical lens by producing a difference in edge thickness, either by grinding the
back surface at an angle to the front surface during lens surfacing or, if the lens
has sufficient power, de-centering the optical center of the lens
1
SUCCESS!
,Page 2 of 61
Compounding Prism - CORRECT ANSWER✔✔BI & BI
BO & BO
BU & BD
Cancelling Prism - CORRECT ANSWER✔✔BI & BO
BD & BD
BU & BU
Prentice's Rule - CORRECT ANSWER✔✔P=hcm x D
P=amount of prism created
h= number of cm OC moved
cm= centimeters (convert to mm, divide by 10)
D= power in meridian with error
Vertical Imbalance - CORRECT ANSWER✔✔The difference in vertical prism power
at the reading level in a pair of lenses.
2
SUCCESS!
,Page 3 of 61
OC Height's by lens - CORRECT ANSWER✔✔SV = 1/2 of B
Progressive = Fitting cross
FT = 5mm above segment
Vertex Compensation - CORRECT ANSWER✔✔A plus lens when moved farther
from the eye gains in plus power
Distance is 0 with CL because they are on the eye
Vertex compensation Formula - CORRECT ANSWER✔✔De= Dl/(1 + d xDl)
De= diopter effective value of error created
D/= lens power (given power)
d= amount in METERS lens moved from refracted position to position lens is worn
Keep sign for what it is (+/-)
- to d means moves away
Horizontal Centration - CORRECT ANSWER✔✔PD
3
SUCCESS!
, Page 4 of 61
Vertical Centration - CORRECT ANSWER✔✔OC
Horizontal & Vertical Centration Formula - CORRECT ANSWER✔✔Given PD/OC -
Human PD/OC= mm moved
Frame PD is found by adding A+DBL
Power in Oblique Meridians - CORRECT ANSWER✔✔Dt= (sina)²x Dc +Ds
Dt= Total Power we need
(sina)²= degree we have degree we need
Dc= cylinder power
Ds= sphere power
Lensmeter - CORRECT ANSWER✔✔is an ophthalmic instrument. It is mainly used
by optometrists and opticians to verify the correct prescription in a pair of
eyeglasses, to properly orient and mark uncut lenses, and to confirm the correct
mounting of lenses in spectacle frames. (also known as a focimeter or vertometer)
4
SUCCESS!
