ABO Practical broken down based on
the ABO-NCLE practical Exam
Candidate HandbookPractical Test
Specifications sheet (ABO Practical)
Questions and Answers 2024 With
Complete Solution
Single Vision - CORRECT ANS corrects for one distance
Multifocal - CORRECT ANS Corrects with two or more prescriptions (or 'powers')
Bifocal - CORRECT ANS lens having two focus strengths
Trifocal - CORRECT ANS pertaining to having three focus strengths
Calculating Prismatic Effects - CORRECT ANS 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
Compounding Prism - CORRECT ANS BI & BI
BO & BO
BU & BD
Cancelling Prism - CORRECT ANS BI & BO
BD & BD
BU & BU
Prentice's Rule - CORRECT ANS 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 ANS The difference in vertical prism power at the
reading level in a pair of lenses.
OC Height's by lens - CORRECT ANS SV = 1/2 of B
Progressive = Fitting cross
FT = 5mm above segment
Vertex Compensation - CORRECT ANS 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 ANS 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 ANS PD
Vertical Centration - CORRECT ANS OC
Horizontal & Vertical Centration Formula - CORRECT ANS Given PD/OC -
Human PD/OC= mm moved
Frame PD is found by adding A+DBL
Power in Oblique Meridians - CORRECT ANS Dt= (sina)²x Dc +Ds
Dt= Total Power we need
, ABO Practical broken down based on
the ABO-NCLE practical Exam
Candidate HandbookPractical Test
Specifications sheet (ABO Practical)
Questions and Answers 2024 With
Complete Solution
(sina)²= degree we have degree we need
Dc= cylinder power
Ds= sphere power
Lensmeter - CORRECT ANS 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)
Lens Measurement Devices - CORRECT ANS lens clock, calipers, millimeter
ruler, circumference gauge
Lens Clock - CORRECT ANS is used to measure the surface powers base curve
of a lens
Lens Calipers - CORRECT ANS Measures thickness of lenses in mm
Millimeter ruler - CORRECT ANS measures interpupillary distance, or seg
heights, or OC heights
Circumference gauge - CORRECT ANS For quick and accurate measurements of
lenses or patterns.
Corneal reflex Pupilometer - CORRECT ANS for precisely measuring and digitally
recording pupillary distances. Used for measuring of monocular and binocular
Hand Tools - CORRECT ANS Screwdrivers, needle-nose pliers, tweezers, files
scratchless screwdriver - CORRECT ANS for working on drill mount or facetted
lenses
pickup screwdriver - CORRECT ANS jaws with spring tension to hold screws
while you put them in place, available with either type blade
Big Brass screwdriver - CORRECT ANS unscrew most screw, with a large brass
handle
plastic top screwdriver - CORRECT ANS most popular and most dangerous
Pad Popper - CORRECT ANS used to remove snap-in nosepads without
changing the alignment of the adjustable guard arms. the prongs are inserted behind
the nosepad and in front of the nosepad box. a simple twist removes the pad
Rimless mounting tool - CORRECT ANS the hook is started at the hinge side of
the nylon line that pulls around the lens. use caution, easy to chip lens
eyewire sizing pliers - CORRECT ANS used to check the size of the lens without
damaging the barrels of the frame
lens axis pliers - CORRECT ANS allow you to turn the lens to adjust the axis
while it is mounted in the frame
Flat/round Nose Pliers - CORRECT ANS used to change the curvature of pad
arm loops. positioned so the loop is bent around the round tip
Nylon Jaw flat/round nose pliers or Half-padded pliers - CORRECT ANS they are
used to protect the finish of metal frames during adjustments. nylon side should be
positioned against the visible part of the frame
the ABO-NCLE practical Exam
Candidate HandbookPractical Test
Specifications sheet (ABO Practical)
Questions and Answers 2024 With
Complete Solution
Single Vision - CORRECT ANS corrects for one distance
Multifocal - CORRECT ANS Corrects with two or more prescriptions (or 'powers')
Bifocal - CORRECT ANS lens having two focus strengths
Trifocal - CORRECT ANS pertaining to having three focus strengths
Calculating Prismatic Effects - CORRECT ANS 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
Compounding Prism - CORRECT ANS BI & BI
BO & BO
BU & BD
Cancelling Prism - CORRECT ANS BI & BO
BD & BD
BU & BU
Prentice's Rule - CORRECT ANS 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 ANS The difference in vertical prism power at the
reading level in a pair of lenses.
OC Height's by lens - CORRECT ANS SV = 1/2 of B
Progressive = Fitting cross
FT = 5mm above segment
Vertex Compensation - CORRECT ANS 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 ANS 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 ANS PD
Vertical Centration - CORRECT ANS OC
Horizontal & Vertical Centration Formula - CORRECT ANS Given PD/OC -
Human PD/OC= mm moved
Frame PD is found by adding A+DBL
Power in Oblique Meridians - CORRECT ANS Dt= (sina)²x Dc +Ds
Dt= Total Power we need
, ABO Practical broken down based on
the ABO-NCLE practical Exam
Candidate HandbookPractical Test
Specifications sheet (ABO Practical)
Questions and Answers 2024 With
Complete Solution
(sina)²= degree we have degree we need
Dc= cylinder power
Ds= sphere power
Lensmeter - CORRECT ANS 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)
Lens Measurement Devices - CORRECT ANS lens clock, calipers, millimeter
ruler, circumference gauge
Lens Clock - CORRECT ANS is used to measure the surface powers base curve
of a lens
Lens Calipers - CORRECT ANS Measures thickness of lenses in mm
Millimeter ruler - CORRECT ANS measures interpupillary distance, or seg
heights, or OC heights
Circumference gauge - CORRECT ANS For quick and accurate measurements of
lenses or patterns.
Corneal reflex Pupilometer - CORRECT ANS for precisely measuring and digitally
recording pupillary distances. Used for measuring of monocular and binocular
Hand Tools - CORRECT ANS Screwdrivers, needle-nose pliers, tweezers, files
scratchless screwdriver - CORRECT ANS for working on drill mount or facetted
lenses
pickup screwdriver - CORRECT ANS jaws with spring tension to hold screws
while you put them in place, available with either type blade
Big Brass screwdriver - CORRECT ANS unscrew most screw, with a large brass
handle
plastic top screwdriver - CORRECT ANS most popular and most dangerous
Pad Popper - CORRECT ANS used to remove snap-in nosepads without
changing the alignment of the adjustable guard arms. the prongs are inserted behind
the nosepad and in front of the nosepad box. a simple twist removes the pad
Rimless mounting tool - CORRECT ANS the hook is started at the hinge side of
the nylon line that pulls around the lens. use caution, easy to chip lens
eyewire sizing pliers - CORRECT ANS used to check the size of the lens without
damaging the barrels of the frame
lens axis pliers - CORRECT ANS allow you to turn the lens to adjust the axis
while it is mounted in the frame
Flat/round Nose Pliers - CORRECT ANS used to change the curvature of pad
arm loops. positioned so the loop is bent around the round tip
Nylon Jaw flat/round nose pliers or Half-padded pliers - CORRECT ANS they are
used to protect the finish of metal frames during adjustments. nylon side should be
positioned against the visible part of the frame
