NCLE 2 Practice Test| QUESTIONS WITH COMPLETE SOLUTIONS
The tear film consists of which the following?
a. aqueous layer
b. conjunctiva
c. lipid film
d. mucin film Correct Answer: a c d
The primary function of the mucin film is to: change the corneal epithelial surface from a
"_________ surface to a ___________ surface" Correct Answer: hydrophobic surface to a
hydrophilic surface
The lipid layer functions primarily to: Correct Answer: prevent evaporation of the tear film
The test which assesses the quantity of tears normally produced is: __________ Correct Answer:
Schimmer
The test which assesses the quality of the tear film is: _______ Correct Answer: BUT
Prospective patients who fall within the following age group generally provide the best prognosis
for successful contact lens fitting: ________ to ________ Correct Answer: 13 to 38
Which of the following would indicate a good prognosis for successful contact lens fitting?
a. adequate manual dexterity
b. regular low astigmatism
c. refractive error less than ± 1.50 D.
d. BUTs longer than 15 seconds Correct Answer: a b d
The base curve of a certain contact lens is equal to 7.5 mm radius of curvature. The equivalent
power in diopters is: __.__ Correct Answer: 45.00
The primary function of a keratometer is to: measure the "________ of the _________" Correct
Answer: curvature of the cornea
When moved 5 mm from its original position the effective power of a 10.00 diopters lens will
change: "_.__ D" Correct Answer: 0.50 D
When a spectacle lens prescription exceeds ___________ diopters, vertex distance must be
compensated for when determining the power of a contact lens. Correct Answer: ±4.00 D
A spectacle lens is prescribed at -10.00 diopters provided that the lens is fit at a vertex distance
of 10 mm. A rigid contact lens fit "on K" for this patient would require a power of: Correct
Answer: -9.00 D
Spectacle Rx = +10.00 D
Vertex distance = 10 mm
, A rigid contact lens fit "on K" would require the following power: Correct Answer: +11.00 D
Rx: - 4.00 + 1.00 x 90
K: 42.50 at 180/ 43.50 at 90
A rigid contact lens fit "on K" would require the following power: Correct Answer: -3.00 D
Rx: - 4.00 + 1.00 x 90
K: 42.50 at 180/ 43.50 at 90
The power of the lacrimal lens in the question is: Correct Answer: plano
Rx: +11.00 +1.00 x 20 Vertex distance = 12 mm
Ks: 46.25/47.25
What would be the power of a rigid contact lens fit "on K?" Correct Answer: +14.00 D
The transition zone between the sclera and the cornea is called: _______ _________ Correct
Answer: limbal area
Moderate to high myopes often provide a good prognosis for contact lens wear. This may be
because:
a. they are highly motivated
b. Peripheral vision is improved
c. the image is a size larger
d. all of the above Correct Answer: d (all of the above)
Rx: - 3.00 - 0.50 x 90 Vertex distance = 11 mm
What is the power of a rigid contact lens fit 0.50 D steeper than the flattest corneal meridian?
Assume all the astigmatism is in the cornea. Correct Answer: -3.50 D
Rx: - 2.50 + 0.25 x 90 Vertex distance = 12 mm
If a contact lens is to be fit 0.75 diopters steeper than the flattest corneal meridian, what would
the power be?
Assume all the astigmatism is in the cornea. Correct Answer: -3.00 D
The thickness and power of the lacrimal lens will vary with the: ________-______ __________
Correct Answer: lens-cornea relationship
The precorneal tear film provides:
a. a lubricant to the cornea
b. a smooth optical surface for the cornea
c. nutrients to the cornea
d. carbon dioxide Correct Answer: a b c
The corneal curvature at the limbal area closely approximates the curvature of the: Correct
Answer: sclera
The tear film consists of which the following?
a. aqueous layer
b. conjunctiva
c. lipid film
d. mucin film Correct Answer: a c d
The primary function of the mucin film is to: change the corneal epithelial surface from a
"_________ surface to a ___________ surface" Correct Answer: hydrophobic surface to a
hydrophilic surface
The lipid layer functions primarily to: Correct Answer: prevent evaporation of the tear film
The test which assesses the quantity of tears normally produced is: __________ Correct Answer:
Schimmer
The test which assesses the quality of the tear film is: _______ Correct Answer: BUT
Prospective patients who fall within the following age group generally provide the best prognosis
for successful contact lens fitting: ________ to ________ Correct Answer: 13 to 38
Which of the following would indicate a good prognosis for successful contact lens fitting?
a. adequate manual dexterity
b. regular low astigmatism
c. refractive error less than ± 1.50 D.
d. BUTs longer than 15 seconds Correct Answer: a b d
The base curve of a certain contact lens is equal to 7.5 mm radius of curvature. The equivalent
power in diopters is: __.__ Correct Answer: 45.00
The primary function of a keratometer is to: measure the "________ of the _________" Correct
Answer: curvature of the cornea
When moved 5 mm from its original position the effective power of a 10.00 diopters lens will
change: "_.__ D" Correct Answer: 0.50 D
When a spectacle lens prescription exceeds ___________ diopters, vertex distance must be
compensated for when determining the power of a contact lens. Correct Answer: ±4.00 D
A spectacle lens is prescribed at -10.00 diopters provided that the lens is fit at a vertex distance
of 10 mm. A rigid contact lens fit "on K" for this patient would require a power of: Correct
Answer: -9.00 D
Spectacle Rx = +10.00 D
Vertex distance = 10 mm
, A rigid contact lens fit "on K" would require the following power: Correct Answer: +11.00 D
Rx: - 4.00 + 1.00 x 90
K: 42.50 at 180/ 43.50 at 90
A rigid contact lens fit "on K" would require the following power: Correct Answer: -3.00 D
Rx: - 4.00 + 1.00 x 90
K: 42.50 at 180/ 43.50 at 90
The power of the lacrimal lens in the question is: Correct Answer: plano
Rx: +11.00 +1.00 x 20 Vertex distance = 12 mm
Ks: 46.25/47.25
What would be the power of a rigid contact lens fit "on K?" Correct Answer: +14.00 D
The transition zone between the sclera and the cornea is called: _______ _________ Correct
Answer: limbal area
Moderate to high myopes often provide a good prognosis for contact lens wear. This may be
because:
a. they are highly motivated
b. Peripheral vision is improved
c. the image is a size larger
d. all of the above Correct Answer: d (all of the above)
Rx: - 3.00 - 0.50 x 90 Vertex distance = 11 mm
What is the power of a rigid contact lens fit 0.50 D steeper than the flattest corneal meridian?
Assume all the astigmatism is in the cornea. Correct Answer: -3.50 D
Rx: - 2.50 + 0.25 x 90 Vertex distance = 12 mm
If a contact lens is to be fit 0.75 diopters steeper than the flattest corneal meridian, what would
the power be?
Assume all the astigmatism is in the cornea. Correct Answer: -3.00 D
The thickness and power of the lacrimal lens will vary with the: ________-______ __________
Correct Answer: lens-cornea relationship
The precorneal tear film provides:
a. a lubricant to the cornea
b. a smooth optical surface for the cornea
c. nutrients to the cornea
d. carbon dioxide Correct Answer: a b c
The corneal curvature at the limbal area closely approximates the curvature of the: Correct
Answer: sclera
