NCLE ADVANCED CERTIFICATION TEST ACTUAL EXAM
COMPLETE QUESTIONS DETAILED VERIFIED ANSWERS
A+ GRADE ASSURED 2024 UPDATE
• The sagittal depth of a rigid gas permeable contact lens can be altered without changing
the diameter by:
• Changing the power
• Changing the edge design
• Changing the radius of curvature of the anterior optical zone
• Changing the radius of curvature of the posterior optical zone -Answer✅ The answer is D.
The posterior optical zone will directly affect the lens to cornea relationship of a rigid gas
permeable lens. If the posterior optical zone is steepened, it will increase the sagittal depth. If
it is flattened, it will decrease the sagittal depth. Changing the power, which is accomplished
by changing the anterior optical zone, will not affect the sagittal depth of the lens, nor will
changing its edge design.
• A truncation is used on a rigid gas permeable contact lens to help enhance the
performance of which type of design?
• Bifocal
• Aphakic
• Bitoric
• Keratoconus -Answer✅ The answer is A.
A lens is truncated by removing a segment of the lower edge of a contact lens. This creates
a straight edge that interacts with the lower lid and aids in lens positioning. Of the lens
designs listed in the question, the only one that requires precise positioning of its optical
portions is a translating bifocal lens.
,• The mass of an aphakic rigid gas permeable contact lens can be reduced by making the
lens design:
• Spherical
• Lenticular
• Tricurve
• Aspheric -Answer✅ The answer is B.
A lenticular or myoflange design will decrease the mass of an aphakic lens as well as increase
the edge profile, which allows it to interact more with the upper lid and aid in positioning of
the lens.
• In order to tighten the fit of a rigid gas permeable lens you can:
I. Increase the optical zone diameter
• Decrease the optical zone diameter
• Increase the overall lens diameter
• Use a prism ballasted lens design
• 3 only
• 1&3
• 2 only
• 2&3 -Answer✅ The answer is B.
Increasing the optical zone diameter and increasing the overall lens diameter will both
tighten and steepen the relationship of the lens to the cornea. Decreasing the optic zone
diameter will serve to flatten and loosen the lens to cornea relationship. Using a prism-
ballasted lens design will not affect the lens to cornea relationship as it relates to sagittal
depth.
• A high minus rigid gas permeable lens will be thin centrally with relatively thick edges.
To reduce the edge thickness, and increase overall comfort, use:
,• Aspheric peripheral curves
• A myoflange
• A higher Dk material
• A hyperflange -Answer✅ The answer is D.
A hyperflange will decrease edge thickness as well as lens awareness . Aspheric peripheral
curves change the posterior design of the lens but do not reduce edge thickness. A higher Dk
material will not change the overall lens edge thickness. A myoflange will actually add
thickness to the lens edge and is used for high plus lenses not high minus lenses.
• To add minus power to a rigid contact lens with a rotating modifying spindle, one would:
• Polish the posterior surface of the rigid lens
• Polish the mid peripheral anterior surface
• Polish the central anterior surface
• Polish the peripheral anterior surface -Answer✅ The answer is C.
• Which lens design would provide the best visual acuity for a patient with the
following information?
K's 42.00@ 180/
42.50@90 Rx -6.75 +1.75
cx 90
• Front surface toric rigid gas permeable
• Spherical rigid gas permeable
• Soft sphere
• Bitoric rigid gas permeable -Answer✅ The answer is A.
, The keratometer readings indicate the need for a spherical back surface, which would rule out
the use of a bitoric lens. A soft spherical lens would not correct the moderate amount of
has a toric front surface which would correct the residual astigmatism.
• Which of the following describes the angle that the edge of a bead of water makes with
the surface of a plastic?
• Wetting angle
• Surface angle
• Bead angle
• Reflection angle -Answer✅ The answer is A.
The wetting angle of a rigid gas permeable material describes how a fluid spreads over the
surface. It is important to remember, however, that wetting angle is a description of the
material outside of the patient's natural ocular environment. Within minutes of insertion, a
rigid lens is encapsulated in the natural tear mucin and the wetting angle of the material is no
longer important.
• If a patient has 1.50 D of refractive cylinder and keratometer readings of 44.00@ 180/ 44
.50 @ 90, a spherical rigid gas permeable lens will:
• Give the patient their best correctable vision
• Usually result in residual astigmatism
• Fit poorly
• Be uncomfortable -Answer✅ The answer is B.
The back surface of a rigid lens will usually correct only the astigmatism that is found on the
surface of the cornea. Therefore, when there is significantly more astigmatism in the
refraction than on the surface of the cornea, residual astigmatism is anticipated.
• If a patient has spherical K readings of 43.50 and an Rx of -4.00 +1.75 cx 90, the patient has:
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