ABO-NCLE practical Exam questions with correct answers
Question :Single Vision
Correct answer:corrects for one distance
Question :Multifocal
Correct answer:Corrects with two or more prescriptions (or
'powers')
Question :Bifocal
Correct answer:lens having two focus strengths
Question :Trifocal
Correct answer:pertaining to having three focus strengths
Question :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
Question :Compounding Prism
Correct answer:BI & BI
BO & BO BU & BD
Question :Cancelling Prism
Correct answer:BI & BO
BD & BD BU & BU
Question :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
Question :Vertical Imbalance
Correct answer:The difference in vertical prism power at the
reading level in a pair of lenses.
Question :OC Height's by lens
Correct answer:SV = 1/2 of B
Progressive = Fitting cross FT = 5mm above segment
Question :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
Question :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
Question :Horizontal Centration
Correct answer:PD
Question :Vertical Centration
Correct answer:OC
Question :Horizontal & Vertical Centration Formula
Correct answer:Given PD/OC - Human PD/OC= mm moved
Frame PD is found by adding A+DBL
Question :Power in Oblique Meridians
Correct answer:Dt= (sina)²x Dc +Ds
Dt= Total Power we need