ABO-NCLE practical Exam questions with correct answers
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
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.
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
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
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
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.
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
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
