NCLE Advanced Certification Exam Questions and
Answers 100% Correct
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.
6. To add minus power to a rigid contact lens with a rotating modifying spindle, one would:
A. Polish the posterior surface of the rigid lens
B. Polish the mid peripheral anterior surface
C. Polish the central anterior surface
D. Polish the peripheral anterior surface -Answer The answer is C.
One would rarely polish or attempt to manipulate the central posterior surface of a rigid lens.
Applying polishing pressure to the mid-peripheral and the peripheral anterior surface would
add
plus power. Applying polishing pressure to the central anterior surface would add minus
power.
7. 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
A. Front surface toric rigid gas permeable
B. Spherical rigid gas permeable
C. Soft sphere
D. 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
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 spherical back surface,
but
has a toric front surface which would correct the residual astigmatism.
8. Which of the following describes the angle that the edge of a bead of water makes with the
surface of a plastic?
A. Wetting angle
B. Surface angle
C. Bead angle
,D. 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.
9. 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:
A. Give the patient their best correctable vision
B. Usually result in residual astigmatism
C. Fit poorly
D. Be uncomfortable -Answer The answer is B.
1. The sagittal depth of a rigid gas permeable contact lens can be altered without changing
the
diameter by:
, A. Changing the power
B. Changing the edge design
C. Changing the radius of curvature of the anterior optical zone
D. 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.
2. A truncation is used on a rigid gas permeable contact lens to help enhance the performance
of which type of design?
A. Bifocal
B. Aphakic
C. Bitoric
D. 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
Answers 100% Correct
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.
6. To add minus power to a rigid contact lens with a rotating modifying spindle, one would:
A. Polish the posterior surface of the rigid lens
B. Polish the mid peripheral anterior surface
C. Polish the central anterior surface
D. Polish the peripheral anterior surface -Answer The answer is C.
One would rarely polish or attempt to manipulate the central posterior surface of a rigid lens.
Applying polishing pressure to the mid-peripheral and the peripheral anterior surface would
add
plus power. Applying polishing pressure to the central anterior surface would add minus
power.
7. 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
A. Front surface toric rigid gas permeable
B. Spherical rigid gas permeable
C. Soft sphere
D. 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
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 spherical back surface,
but
has a toric front surface which would correct the residual astigmatism.
8. Which of the following describes the angle that the edge of a bead of water makes with the
surface of a plastic?
A. Wetting angle
B. Surface angle
C. Bead angle
,D. 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.
9. 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:
A. Give the patient their best correctable vision
B. Usually result in residual astigmatism
C. Fit poorly
D. Be uncomfortable -Answer The answer is B.
1. The sagittal depth of a rigid gas permeable contact lens can be altered without changing
the
diameter by:
, A. Changing the power
B. Changing the edge design
C. Changing the radius of curvature of the anterior optical zone
D. 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.
2. A truncation is used on a rigid gas permeable contact lens to help enhance the performance
of which type of design?
A. Bifocal
B. Aphakic
C. Bitoric
D. 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
