NCLE Test Review Questions with
Complete Solutions16
Test that measures the quality of tears - ANSWERS-B.U.T. Test (Break up time)
What is the O2 Permeability - ANSWERS-DK values of a lens
What are the disadvantages of Soft Lenses? - ANSWERS-Doesn't correct irregular astigmatism,
favors deposit formation
Which test measures the quantity of tears? - ANSWERS-The Schirmer test.
What are good results for the Schirmer test? - ANSWERS-15 mm in 5 minutes.
What are dry eye results for the Schirmer test? - ANSWERS-5-10 mm in 5 minutes.
Neovascularization is mainly due to what? - ANSWERS-Hypoxia, corneal edema, tight contact
lens fit
The Radii and Power of an average cornea - ANSWERS-7.85 mm or 43.00 D
What are the layers of the cornea? - ANSWERS-Epithelium, Bowman's membrane, Stroma,
Descemet's membrane, Endothelium
The main disadvantage of soft contact lenses - ANSWERS-Protein deposits
,What is it called when contact lenses are used to correct high myopia? - ANSWERS-
Orthokeratology (Ortho-K)
A contact lens with diameter that is larger than the cornea is a hydrophobic or hydrophilic lens?
- ANSWERS-Hydrophilic lens
Which of the following curves indicates the flattest base curve:7.50 mm, 37.50 D, 8.60 mm,
49.00 D? - ANSWERS-37.50 D
A CTL was ordered with a BC of 7.85 mm but was received from the lab with a BC of 7.80 mm.
The BC of the actual lens is _____. - ANSWERS-.25 D steeper than the ordered CTL.
A CTL with a BC of 7.42 mm is fitting too, a tighter fit may be achieved by changing the base
curve to: 7.46 , 7.85 mm, 8.04 mm, none of these? - ANSWERS-none of these... S.S.S. rule
A CTL has a BC of 7.50 mm, what would the PPC most likely be? 7.45 mm, 42.50 D, 7.35 mm,
30.00 D - ANSWERS-30.00 D= 11.25 mm/S.S.S. Rule
What does the term haptic Lens refer to? - ANSWERS-A scleral CTL size
The secondary curve of a RGP CTL is generally flatter or steeper than the CPC and by how much?
- ANSWERS-flatter by 2-4 diopters
When the power of a curve changes by 0.50 D, the radius of curvature changes by
approximately how much? - ANSWERS-0.10 mm
When the CPC of a CTL measures 7.5 mm radius, how much is the power in diopters? -
ANSWERS-45.00 D
, A soft CTL demonstrates excessive movement. This can be fixed with a lens that has a
_________ diameter. - ANSWERS-Larger Diameter. (larger diameter-steeper fit=tighter fit)
HEMA is an abbreviation commonly used to describe what lens? - ANSWERS-The chemicalname
for soft CTL
What is the main reason to utilize a ballasted CTL? - ANSWERS-To have less rotation of the CTL
(Usually used in bifocal CTL's).
The Central portion of the back surface of the CTL is called _________. - ANSWERS-CPC (Central
posterior curve) or the Base Curve (BC) or the optic zone.
The distance between a flat surface and the back surface of the central portion of the lens is
called the ____________. - ANSWERS-Sagital depth (vault, height)
A loose fitting CTL can be made to fit tighter by ____________ the radius of the CPC. -
ANSWERS-shortening the radius of the CPC. S.S.S. Rule
What is an example of a hydrophilic lens material? - ANSWERS-HEMA
A contact lens in which the anterior surface contains two different radii of curvature and the
posterior surface is spherical is called a __________. - ANSWERS-front surface toric.
The central portion of a CTL which contains the refractive power of the CTL is the
_____________. - ANSWERS-Optic Zone (OZ)
A CTL which contains two curves, one base curve and one secondary curve. - ANSWERS-Bicurve
CTL
Complete Solutions16
Test that measures the quality of tears - ANSWERS-B.U.T. Test (Break up time)
What is the O2 Permeability - ANSWERS-DK values of a lens
What are the disadvantages of Soft Lenses? - ANSWERS-Doesn't correct irregular astigmatism,
favors deposit formation
Which test measures the quantity of tears? - ANSWERS-The Schirmer test.
What are good results for the Schirmer test? - ANSWERS-15 mm in 5 minutes.
What are dry eye results for the Schirmer test? - ANSWERS-5-10 mm in 5 minutes.
Neovascularization is mainly due to what? - ANSWERS-Hypoxia, corneal edema, tight contact
lens fit
The Radii and Power of an average cornea - ANSWERS-7.85 mm or 43.00 D
What are the layers of the cornea? - ANSWERS-Epithelium, Bowman's membrane, Stroma,
Descemet's membrane, Endothelium
The main disadvantage of soft contact lenses - ANSWERS-Protein deposits
,What is it called when contact lenses are used to correct high myopia? - ANSWERS-
Orthokeratology (Ortho-K)
A contact lens with diameter that is larger than the cornea is a hydrophobic or hydrophilic lens?
- ANSWERS-Hydrophilic lens
Which of the following curves indicates the flattest base curve:7.50 mm, 37.50 D, 8.60 mm,
49.00 D? - ANSWERS-37.50 D
A CTL was ordered with a BC of 7.85 mm but was received from the lab with a BC of 7.80 mm.
The BC of the actual lens is _____. - ANSWERS-.25 D steeper than the ordered CTL.
A CTL with a BC of 7.42 mm is fitting too, a tighter fit may be achieved by changing the base
curve to: 7.46 , 7.85 mm, 8.04 mm, none of these? - ANSWERS-none of these... S.S.S. rule
A CTL has a BC of 7.50 mm, what would the PPC most likely be? 7.45 mm, 42.50 D, 7.35 mm,
30.00 D - ANSWERS-30.00 D= 11.25 mm/S.S.S. Rule
What does the term haptic Lens refer to? - ANSWERS-A scleral CTL size
The secondary curve of a RGP CTL is generally flatter or steeper than the CPC and by how much?
- ANSWERS-flatter by 2-4 diopters
When the power of a curve changes by 0.50 D, the radius of curvature changes by
approximately how much? - ANSWERS-0.10 mm
When the CPC of a CTL measures 7.5 mm radius, how much is the power in diopters? -
ANSWERS-45.00 D
, A soft CTL demonstrates excessive movement. This can be fixed with a lens that has a
_________ diameter. - ANSWERS-Larger Diameter. (larger diameter-steeper fit=tighter fit)
HEMA is an abbreviation commonly used to describe what lens? - ANSWERS-The chemicalname
for soft CTL
What is the main reason to utilize a ballasted CTL? - ANSWERS-To have less rotation of the CTL
(Usually used in bifocal CTL's).
The Central portion of the back surface of the CTL is called _________. - ANSWERS-CPC (Central
posterior curve) or the Base Curve (BC) or the optic zone.
The distance between a flat surface and the back surface of the central portion of the lens is
called the ____________. - ANSWERS-Sagital depth (vault, height)
A loose fitting CTL can be made to fit tighter by ____________ the radius of the CPC. -
ANSWERS-shortening the radius of the CPC. S.S.S. Rule
What is an example of a hydrophilic lens material? - ANSWERS-HEMA
A contact lens in which the anterior surface contains two different radii of curvature and the
posterior surface is spherical is called a __________. - ANSWERS-front surface toric.
The central portion of a CTL which contains the refractive power of the CTL is the
_____________. - ANSWERS-Optic Zone (OZ)
A CTL which contains two curves, one base curve and one secondary curve. - ANSWERS-Bicurve
CTL
