NCLE - Domain IV Exam Questions &
Answers5
How do you calculate spherical equivalent? - ANSWERS-1/2 the refractive cylinder added to the
sphere
If most of the astigmatism is internal, choose a soft toric lens that has the cylinder
ground____________ - ANSWERS-on the front
What soft toric lens design should you choose for -2.75-1.75x180 "K" 42.25x180 42.75x90 -
ANSWERS-front toric soft lens
What soft toric lens design should you choose for -3.50-1.75x180 "K" 42.00/43.75x90 -
ANSWERS-back toric soft lens
_________ provides a better physical fit and has a better stabilizing effect on the eye for
patients with corneal astigmatism. - ANSWERS-Back toric soft lens
If all astigmatism is on the cornea, choose a soft toric design where the cylinder is
ground_______________. - ANSWERS-on the back
The cylinder axis is only correct if __________________. - ANSWERS-the lens continues to
orient at the position compensated for
If the trial lens has a cylinder power, over refract with ______________. - ANSWERS-spheres
only
, With LARS, if the relative difference is counterclockwise, ______________ difference from the
spectacle Rx, not the trial lens axis. - ANSWERS-subtract
With LARS, if the relative difference is clockwise, ______________ difference from the spectacle
Rx, not the trial lens axis. - ANSWERS-add
lens rotates to the right 20 degrees with the precription of -3.00-1.75x180. What new lens
should be ordered? - ANSWERS--3.00-1.75x160
What is LARS? - ANSWERS-Left Add, Right Subtract
How to compensate for axial alignment - ANSWERS-1. Locate the base prism mark or lens
marking consistent with that lens brand.
2. Estimate displacement from center line
3. Compensate axis from Spectacle Rx.
4. Observe then measure and correct
How do you choose a base curve for soft toric lenses? - ANSWERS->45.00 - fit 8.6 or 8.7
<45.00 - fit 8.7 or 8.9
How do you compensate for vertex distance? - ANSWERS-1. Minus prescriptions from -4.00 on
take less minus at the cornea.
2. Plus prescriptions from +4.00 on take more plus at the cornea.
How do you fit soft toric lenses? - ANSWERS-1. Transpose Rx in minus cylinder form
2. Compensate for vertex distance > +/-4.00
3. Follow the same procedures for choosing a base curve
4. Compensate for alignment
Answers5
How do you calculate spherical equivalent? - ANSWERS-1/2 the refractive cylinder added to the
sphere
If most of the astigmatism is internal, choose a soft toric lens that has the cylinder
ground____________ - ANSWERS-on the front
What soft toric lens design should you choose for -2.75-1.75x180 "K" 42.25x180 42.75x90 -
ANSWERS-front toric soft lens
What soft toric lens design should you choose for -3.50-1.75x180 "K" 42.00/43.75x90 -
ANSWERS-back toric soft lens
_________ provides a better physical fit and has a better stabilizing effect on the eye for
patients with corneal astigmatism. - ANSWERS-Back toric soft lens
If all astigmatism is on the cornea, choose a soft toric design where the cylinder is
ground_______________. - ANSWERS-on the back
The cylinder axis is only correct if __________________. - ANSWERS-the lens continues to
orient at the position compensated for
If the trial lens has a cylinder power, over refract with ______________. - ANSWERS-spheres
only
, With LARS, if the relative difference is counterclockwise, ______________ difference from the
spectacle Rx, not the trial lens axis. - ANSWERS-subtract
With LARS, if the relative difference is clockwise, ______________ difference from the spectacle
Rx, not the trial lens axis. - ANSWERS-add
lens rotates to the right 20 degrees with the precription of -3.00-1.75x180. What new lens
should be ordered? - ANSWERS--3.00-1.75x160
What is LARS? - ANSWERS-Left Add, Right Subtract
How to compensate for axial alignment - ANSWERS-1. Locate the base prism mark or lens
marking consistent with that lens brand.
2. Estimate displacement from center line
3. Compensate axis from Spectacle Rx.
4. Observe then measure and correct
How do you choose a base curve for soft toric lenses? - ANSWERS->45.00 - fit 8.6 or 8.7
<45.00 - fit 8.7 or 8.9
How do you compensate for vertex distance? - ANSWERS-1. Minus prescriptions from -4.00 on
take less minus at the cornea.
2. Plus prescriptions from +4.00 on take more plus at the cornea.
How do you fit soft toric lenses? - ANSWERS-1. Transpose Rx in minus cylinder form
2. Compensate for vertex distance > +/-4.00
3. Follow the same procedures for choosing a base curve
4. Compensate for alignment
