NCLE Advanced Certification Exam |
Contact Lens Technology | Exam Questions
& Verified Answers
Updated
(Verified Questions & Answers)
A+ Grade Guaranteed
,The answer is D. 1. The sagittal depth of a rigid gas permeable contact lens can be altered
The posterior optical zone will directly affect the lens to without changing the diameter by:
cornea relationship of a rigid gas permeable lens. If the
posterior optical zone is steepened, it will increase the A. Changing the power
sagittal depth. If it is flattened, it will decrease the sagittal
depth. Changing the power, which is accomplished by B. Changing the edge design
changing the anterior optical zone, will not affect the C. Changing the radius of curvature of the anterior optical zone
sagittal depth of the lens, nor will changing its edge
design. D. Changing the radius of curvature of the posterior optical zone
The answer is A. 2. A truncation is used on a rigid gas permeable contact lens to help
A lens is truncated by removing a segment of the lower enhance the performance of which type of design?
edge of a contact lens. This creates a straight edge that
interacts with the lower lid and aids in lens positioning. Of A. Bifocal
the lens designs listed in the question, the only one that
requires precise positioning of its optical portions is a B. Aphakic
translating bifocal lens. C. Bitoric
D. Keratoconus
The answer is B. 3. The mass of an aphakic rigid gas permeable contact lens can be reduced
A lenticular or myoflange design will decrease the mass of by making the lens design:
an aphakic lens as well as increase the edge profile, which
allows it to interact more with the upper lid and aid in A. Spherical
positioning of the lens.
B. Lenticular
C. Tricurve
D. Aspheric
The answer is B. 4. In order to tighten the fit of a rigid gas permeable lens you can:
Increasing the optical zone diameter and increasing the I. Increase the optical zone diameter
overall lens diameter will both tighten and steepen the 2. Decrease the optical zone diameter
relationship of the lens to the cornea. Decreasing the optic 3. Increase the overall lens diameter
zone diameter will serve to flatten and loosen the lens to
cornea relationship. Using a prism-ballasted lens design 4. Use a prism ballasted lens design
will not affect the lens to cornea relationship as it relates to
sagittal depth.
A. 3 only
B. 1&3
C. 2 only
D. 2&3
The answer is D. 5. A high minus rigid gas permeable lens will be thin centrally with relatively
A hyperflange will decrease edge thickness as well as lens thick edges. To reduce the edge thickness, and increase overall comfort,
awareness . Aspheric peripheral curves change the use:
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 A. Aspheric peripheral curves
thickness to the lens edge and is used for high plus lenses B. A myoflange
not high minus lenses.
C. A higher Dk material
D. A hyperflange
The answer is C. 6. To add minus power to a rigid contact lens with a rotating modifying
One would rarely polish or attempt to manipulate the spindle, one would:
central posterior surface of a rigid lens. Applying polishing
pressure to the mid-peripheral and the peripheral anterior A. Polish the posterior surface of the rigid lens
surface would add plus power. Applying polishing pressure
to the central anterior surface would add minus power. B. Polish the mid peripheral anterior surface
C. Polish the central anterior surface
D. Polish the peripheral anterior surface
,The answer is A. 7. Which lens design would provide the best visual acuity for a patient with
The keratometer readings indicate the need for a spherical the following information?
back surface, which would rule out the use of a bitoric lens. K's 42.00@ 180/ 42.50@90
A soft spherical lens would not correct the moderate Rx -6.75 +1.75 cx 90
amount of refractive astigmatism that is present, nor would
the spherical rigid gas permeable lens. A front surface toric
RGP would best meet this patient's needs since it has a A. Front surface toric rigid gas permeable
spherical back surface, but has a toric front surface which
B. Spherical rigid gas permeable
would correct the residual astigmatism.
C. Soft sphere
D. Bitoric rigid gas permeable
The answer is A. 8. Which of the following describes the angle that the edge of a bead of
The wetting angle of a rigid gas permeable material water makes with the surface of a plastic?
describes how a fluid spreads over the surface. It is
important to remember, however, that wetting angle is a A. Wetting angle
description of the material outside of the patient's natural
ocular environment. Within minutes of insertion, a rigid B. Surface angle
lens is encapsulated in the natural tear mucin and the C. Bead angle
wetting angle of the material is no longer important.
D. Reflection angle
The answer is B. 9. If a patient has 1.50 D of refractive cylinder and keratometer readings of
The back surface of a rigid lens will usually correct only the 44.00@ 180/ 44 .50 @ 90, a spherical rigid gas permeable lens will:
astigmatism that is found on the surface of the cornea.
Therefore, when there is significantly more astigmatism in A. Give the patient their best correctable vision
the refraction than on the surface of the cornea, residual
astigmatism is anticipated. B. Usually result in residual astigmatism
C. Fit poorly
D. Be uncomfortable
The answer is C. 10. If a patient has spherical K readings of 43.50 and an Rx of -4.00 +1.75
Lenticular astigmatism usually exists when the amount of cx 90, the patient has:
refractive cylinder is greater than the amount of corneal
cylinder. It is assumed that the additional astigmatism A. Corneal astigmatism
originates in the crystalline lens.
B. Against the rule astigmatism
C. Lenticular astigmatism
D. Mixed astigmatism
The answer is B. 11. In which of the following situations is a rigid gas permeable lens always
With regular astigmatism, even high degrees, a soft toric preferred over a soft lens?
lens can work quite effectively. Presbyopic and aphakic
patients can also be successfully fit with soft lenses. A. Regular astigmatism
However, patients with irregular astigmatism will achieve
their best visual acuity only with rigid gas permeable B. Irregular astigmatism
lenses since soft lenses will mold to the corneal contour C. Aphakia
and not mask the irregularity.
D. Presbyopia
The answer is A. 12. In order to steepen the base curve of a rigid gas permeable lens without
Decreasing the optical zone diameter while steepening the changing the lens to cornea relationship, you would also need to:
base curve of a rigid gas permeable lens will allow the lens
to cornea relationship to remain the same, since A. Decrease the optical zone diameter
decreasing the optical zone diameter loosens the lens to
cornea relationship and steepen- ing the base curve B. Decrease the center thickness
tightens the relationship. Increasing the overall lens C. Increase the overall lens diameter
diameter also tightens the fit and will only exaggerate the
change made to the lens to cornea relationship. D. Increase the lens power
Decreasing the center thickness or increasing the lens
power will have no significant effect on the relationship of
the lens to the cornea.
, The answer is B. 13. To steepen the lens to cornea relationship of a rigid gas permeable lens
Increasing the overall lens diameter or increasing the you could :
optical zone diameter will steepen the lens to cornea
relationship. Conversely, decreasing the optical zone A. Increase overall diameter and decrease optical zone diameter
diameter, decreasing the overall lens diameter or flattening
the base curve will loosen the relationship. If one change B. Increase overall diameter and increase optical zone diameter
is made that tightens the relationship and another is made C. Increase optical zone diameter and decrease overall diameter
that loosens it, the changes will cancel each other out.
D. Increase optical zone diameter and flatten base curve
The answer is D. 14. Which is not an indication for modifying a rigid gas permeable lens?
Modification of rigid gas permeable lenses is a valuable
skill and can increase a practitioner's success at RGP A. Corneal staining
fitting. Many in-office modifications can be utilized to B. Poor lens position
improve the positioning of a lens, reduce discomfort for the
patient and eliminate corneal staining. C. Discomfort
D. Surface Wettability
The answer is D. 15. Which of the following modifications can be made to a rigid gas
Many modifi~ations to rigid gas permeable lenses can be permeable lens in the office?
done in the office, saving time and improving service.
Blending peripheral curves, adding minus power, adding A. Blending
plus power, polishing the edges, polishing the anterior and
posterior surfaces, as well as reducing lens diameter are B. Changing the power
all examples of modifications that can be performed in the C. Polishing the edge
office.
D. Changing the base curve
The answer is A. 16. To achieve a lens to cornea relationship that exhibits apical clearance,
Lenses that position temporally or inferiorly are not the lens is designed steeper than the flattest corneal measurement. This
typically indicated and should be avoided. Lenses that lens will most often position:
position superiorly are often lenses that have been
designed with the apical alignment philosophy and have
been fit flatter than the flattest keratometer reading in order A. Centrally
to achieve this alignment. Lenses that are fit with apical B. Temporally
clearance are fit steeper than the flattest corneal
measurement and often will fit intrapalpebrally or centrally. C. Superiorly
D. Inferiorly
The answer is C. 17. Which of the following are visual systems used by rigid gas permeable
The two visual systems utilized by rigid gas permeable bifocal lenses?
bifocals are simultaneous and alternating. With
simultaneous vision systems, both near and far images are A. Translating and hyperopic
received by the retina at the same time. Concentric and
aspheric bifocal lens designs utilize simulta- neous vision B. Simultaneous and instantaneous
principles. With alternating vision systems, the lens will C. Simultaneous and alternating
move on the eye, delivering the focal length that is in front
of the pupil as the lens translates . Segmented bifocal lens D. Truncated and prism ballasted
designs fall into this category.
The answer is D. 18. Which of the following are methods for stabilizing the rotation of rigid
Most translating or alternating rigid gas permeable bifocal bifocal contact lenses?
lenses must be stabilized in
order for the proper segment to align correctly with the A. Back surface toric and front surface toric
pupil. Two methods of accomplishing this are by truncating
and/ or prism ballasting the lens. In truncation, the bottom B. Edge roll and polish
portion of the lens is removed, producing a straight edge C. Alternating and translating
that interacts ·with the lid and aligns the lens in its proper
position. With prism ballasting, the bottom portion of the D. Truncation and prism ballast
lens is made thicker than the top portion. Following the
same principles as prism ballasting of a soft toric lens, the
thicker portion of the lens will be forced from under the
upper lid to an inferior position.
Contact Lens Technology | Exam Questions
& Verified Answers
Updated
(Verified Questions & Answers)
A+ Grade Guaranteed
,The answer is D. 1. The sagittal depth of a rigid gas permeable contact lens can be altered
The posterior optical zone will directly affect the lens to without changing the diameter by:
cornea relationship of a rigid gas permeable lens. If the
posterior optical zone is steepened, it will increase the A. Changing the power
sagittal depth. If it is flattened, it will decrease the sagittal
depth. Changing the power, which is accomplished by B. Changing the edge design
changing the anterior optical zone, will not affect the C. Changing the radius of curvature of the anterior optical zone
sagittal depth of the lens, nor will changing its edge
design. D. Changing the radius of curvature of the posterior optical zone
The answer is A. 2. A truncation is used on a rigid gas permeable contact lens to help
A lens is truncated by removing a segment of the lower enhance the performance of which type of design?
edge of a contact lens. This creates a straight edge that
interacts with the lower lid and aids in lens positioning. Of A. Bifocal
the lens designs listed in the question, the only one that
requires precise positioning of its optical portions is a B. Aphakic
translating bifocal lens. C. Bitoric
D. Keratoconus
The answer is B. 3. The mass of an aphakic rigid gas permeable contact lens can be reduced
A lenticular or myoflange design will decrease the mass of by making the lens design:
an aphakic lens as well as increase the edge profile, which
allows it to interact more with the upper lid and aid in A. Spherical
positioning of the lens.
B. Lenticular
C. Tricurve
D. Aspheric
The answer is B. 4. In order to tighten the fit of a rigid gas permeable lens you can:
Increasing the optical zone diameter and increasing the I. Increase the optical zone diameter
overall lens diameter will both tighten and steepen the 2. Decrease the optical zone diameter
relationship of the lens to the cornea. Decreasing the optic 3. Increase the overall lens diameter
zone diameter will serve to flatten and loosen the lens to
cornea relationship. Using a prism-ballasted lens design 4. Use a prism ballasted lens design
will not affect the lens to cornea relationship as it relates to
sagittal depth.
A. 3 only
B. 1&3
C. 2 only
D. 2&3
The answer is D. 5. A high minus rigid gas permeable lens will be thin centrally with relatively
A hyperflange will decrease edge thickness as well as lens thick edges. To reduce the edge thickness, and increase overall comfort,
awareness . Aspheric peripheral curves change the use:
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 A. Aspheric peripheral curves
thickness to the lens edge and is used for high plus lenses B. A myoflange
not high minus lenses.
C. A higher Dk material
D. A hyperflange
The answer is C. 6. To add minus power to a rigid contact lens with a rotating modifying
One would rarely polish or attempt to manipulate the spindle, one would:
central posterior surface of a rigid lens. Applying polishing
pressure to the mid-peripheral and the peripheral anterior A. Polish the posterior surface of the rigid lens
surface would add plus power. Applying polishing pressure
to the central anterior surface would add minus power. B. Polish the mid peripheral anterior surface
C. Polish the central anterior surface
D. Polish the peripheral anterior surface
,The answer is A. 7. Which lens design would provide the best visual acuity for a patient with
The keratometer readings indicate the need for a spherical the following information?
back surface, which would rule out the use of a bitoric lens. K's 42.00@ 180/ 42.50@90
A soft spherical lens would not correct the moderate Rx -6.75 +1.75 cx 90
amount of refractive astigmatism that is present, nor would
the spherical rigid gas permeable lens. A front surface toric
RGP would best meet this patient's needs since it has a A. Front surface toric rigid gas permeable
spherical back surface, but has a toric front surface which
B. Spherical rigid gas permeable
would correct the residual astigmatism.
C. Soft sphere
D. Bitoric rigid gas permeable
The answer is A. 8. Which of the following describes the angle that the edge of a bead of
The wetting angle of a rigid gas permeable material water makes with the surface of a plastic?
describes how a fluid spreads over the surface. It is
important to remember, however, that wetting angle is a A. Wetting angle
description of the material outside of the patient's natural
ocular environment. Within minutes of insertion, a rigid B. Surface angle
lens is encapsulated in the natural tear mucin and the C. Bead angle
wetting angle of the material is no longer important.
D. Reflection angle
The answer is B. 9. If a patient has 1.50 D of refractive cylinder and keratometer readings of
The back surface of a rigid lens will usually correct only the 44.00@ 180/ 44 .50 @ 90, a spherical rigid gas permeable lens will:
astigmatism that is found on the surface of the cornea.
Therefore, when there is significantly more astigmatism in A. Give the patient their best correctable vision
the refraction than on the surface of the cornea, residual
astigmatism is anticipated. B. Usually result in residual astigmatism
C. Fit poorly
D. Be uncomfortable
The answer is C. 10. If a patient has spherical K readings of 43.50 and an Rx of -4.00 +1.75
Lenticular astigmatism usually exists when the amount of cx 90, the patient has:
refractive cylinder is greater than the amount of corneal
cylinder. It is assumed that the additional astigmatism A. Corneal astigmatism
originates in the crystalline lens.
B. Against the rule astigmatism
C. Lenticular astigmatism
D. Mixed astigmatism
The answer is B. 11. In which of the following situations is a rigid gas permeable lens always
With regular astigmatism, even high degrees, a soft toric preferred over a soft lens?
lens can work quite effectively. Presbyopic and aphakic
patients can also be successfully fit with soft lenses. A. Regular astigmatism
However, patients with irregular astigmatism will achieve
their best visual acuity only with rigid gas permeable B. Irregular astigmatism
lenses since soft lenses will mold to the corneal contour C. Aphakia
and not mask the irregularity.
D. Presbyopia
The answer is A. 12. In order to steepen the base curve of a rigid gas permeable lens without
Decreasing the optical zone diameter while steepening the changing the lens to cornea relationship, you would also need to:
base curve of a rigid gas permeable lens will allow the lens
to cornea relationship to remain the same, since A. Decrease the optical zone diameter
decreasing the optical zone diameter loosens the lens to
cornea relationship and steepen- ing the base curve B. Decrease the center thickness
tightens the relationship. Increasing the overall lens C. Increase the overall lens diameter
diameter also tightens the fit and will only exaggerate the
change made to the lens to cornea relationship. D. Increase the lens power
Decreasing the center thickness or increasing the lens
power will have no significant effect on the relationship of
the lens to the cornea.
, The answer is B. 13. To steepen the lens to cornea relationship of a rigid gas permeable lens
Increasing the overall lens diameter or increasing the you could :
optical zone diameter will steepen the lens to cornea
relationship. Conversely, decreasing the optical zone A. Increase overall diameter and decrease optical zone diameter
diameter, decreasing the overall lens diameter or flattening
the base curve will loosen the relationship. If one change B. Increase overall diameter and increase optical zone diameter
is made that tightens the relationship and another is made C. Increase optical zone diameter and decrease overall diameter
that loosens it, the changes will cancel each other out.
D. Increase optical zone diameter and flatten base curve
The answer is D. 14. Which is not an indication for modifying a rigid gas permeable lens?
Modification of rigid gas permeable lenses is a valuable
skill and can increase a practitioner's success at RGP A. Corneal staining
fitting. Many in-office modifications can be utilized to B. Poor lens position
improve the positioning of a lens, reduce discomfort for the
patient and eliminate corneal staining. C. Discomfort
D. Surface Wettability
The answer is D. 15. Which of the following modifications can be made to a rigid gas
Many modifi~ations to rigid gas permeable lenses can be permeable lens in the office?
done in the office, saving time and improving service.
Blending peripheral curves, adding minus power, adding A. Blending
plus power, polishing the edges, polishing the anterior and
posterior surfaces, as well as reducing lens diameter are B. Changing the power
all examples of modifications that can be performed in the C. Polishing the edge
office.
D. Changing the base curve
The answer is A. 16. To achieve a lens to cornea relationship that exhibits apical clearance,
Lenses that position temporally or inferiorly are not the lens is designed steeper than the flattest corneal measurement. This
typically indicated and should be avoided. Lenses that lens will most often position:
position superiorly are often lenses that have been
designed with the apical alignment philosophy and have
been fit flatter than the flattest keratometer reading in order A. Centrally
to achieve this alignment. Lenses that are fit with apical B. Temporally
clearance are fit steeper than the flattest corneal
measurement and often will fit intrapalpebrally or centrally. C. Superiorly
D. Inferiorly
The answer is C. 17. Which of the following are visual systems used by rigid gas permeable
The two visual systems utilized by rigid gas permeable bifocal lenses?
bifocals are simultaneous and alternating. With
simultaneous vision systems, both near and far images are A. Translating and hyperopic
received by the retina at the same time. Concentric and
aspheric bifocal lens designs utilize simulta- neous vision B. Simultaneous and instantaneous
principles. With alternating vision systems, the lens will C. Simultaneous and alternating
move on the eye, delivering the focal length that is in front
of the pupil as the lens translates . Segmented bifocal lens D. Truncated and prism ballasted
designs fall into this category.
The answer is D. 18. Which of the following are methods for stabilizing the rotation of rigid
Most translating or alternating rigid gas permeable bifocal bifocal contact lenses?
lenses must be stabilized in
order for the proper segment to align correctly with the A. Back surface toric and front surface toric
pupil. Two methods of accomplishing this are by truncating
and/ or prism ballasting the lens. In truncation, the bottom B. Edge roll and polish
portion of the lens is removed, producing a straight edge C. Alternating and translating
that interacts ·with the lid and aligns the lens in its proper
position. With prism ballasting, the bottom portion of the D. Truncation and prism ballast
lens is made thicker than the top portion. Following the
same principles as prism ballasting of a soft toric lens, the
thicker portion of the lens will be forced from under the
upper lid to an inferior position.
