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ABO Practice Test(Questions and Answers 100%
correct)
When discussing thick lenses, the factors which are
considered in computing the lens power are:
a. front curve, thickness and index
b. back curve, thickness and index
c. front curve, back curve and thickness
d. front curve, back curve, thickness and index -
.....ANSWER ...✔✔ d. front curve, back curve,
thickness and index
Toric transposition shows:
a. lens thickness
b. power in principal meridians
c. the power of the ADD
d. the lens diameter - .....ANSWER ...✔✔ b. power in
principal meridians
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Increasing the diameter of a minus power lens always
increases its:
a. vertex power
b. center thickness
c. weight
d. refractive index - .....ANSWER ...✔✔ c. weight
The optical center of a round segment is located:
a. at the very top of the segment
b. in the geometric center of the segment
c. 5 mm from the top of the segment
d. at the very bottom of the segment - .....ANSWER
...✔✔ b. in the geometric center of the segment
The base curve of any multifocal lens is found on the
surface containing the:
a. cross curve
b. cylinder surface
c. segment
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d. ocular curve - .....ANSWER ...✔✔ c. segment
Normal slab-off (bicentric grind) is ground on the lens
whose vertical meridian has the:
a. strongest curves
b. most plus power
c. least plus power
d. least minus power - .....ANSWER ...✔✔ c. least plus
power
The refractive error indicated by the Rx +1.75 -2.75 x
090 is:
a. compound hyperopic astigmatism
b. compound myopic astigmatism
c. simple myopic astigmatism
d. mixed astigmatism - .....ANSWER ...✔✔ d. mixed
astigmatism
Tempering a lens by heat treating results in a lens being:
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a. less resistant to impact
b. more resistant to impact
c. more resistant to surface scratching
d. impossible to break - .....ANSWER ...✔✔ b. more
resistant to impact
A slab-off lens is for the correction of:
a. astigmatic errors
b. excessive weight of lens
c. excessive prism imbalance at the reading level
d. exotropia - .....ANSWER ...✔✔ c. excessive prism
imbalance at the reading level
Chem-tempering makes a glass lens more impact
resistant by placing the lens in a potassium nitrate bath.
The lens undergoes a process known as:
a. ion exchange
b. iron oxide activation
c. silver halide transfer
d. thermal bleaching - .....ANSWER ...✔✔ a. ion
exchange
ABO Practice Test(Questions and Answers 100%
correct)
When discussing thick lenses, the factors which are
considered in computing the lens power are:
a. front curve, thickness and index
b. back curve, thickness and index
c. front curve, back curve and thickness
d. front curve, back curve, thickness and index -
.....ANSWER ...✔✔ d. front curve, back curve,
thickness and index
Toric transposition shows:
a. lens thickness
b. power in principal meridians
c. the power of the ADD
d. the lens diameter - .....ANSWER ...✔✔ b. power in
principal meridians
,2|Page
Increasing the diameter of a minus power lens always
increases its:
a. vertex power
b. center thickness
c. weight
d. refractive index - .....ANSWER ...✔✔ c. weight
The optical center of a round segment is located:
a. at the very top of the segment
b. in the geometric center of the segment
c. 5 mm from the top of the segment
d. at the very bottom of the segment - .....ANSWER
...✔✔ b. in the geometric center of the segment
The base curve of any multifocal lens is found on the
surface containing the:
a. cross curve
b. cylinder surface
c. segment
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d. ocular curve - .....ANSWER ...✔✔ c. segment
Normal slab-off (bicentric grind) is ground on the lens
whose vertical meridian has the:
a. strongest curves
b. most plus power
c. least plus power
d. least minus power - .....ANSWER ...✔✔ c. least plus
power
The refractive error indicated by the Rx +1.75 -2.75 x
090 is:
a. compound hyperopic astigmatism
b. compound myopic astigmatism
c. simple myopic astigmatism
d. mixed astigmatism - .....ANSWER ...✔✔ d. mixed
astigmatism
Tempering a lens by heat treating results in a lens being:
, 4|Page
a. less resistant to impact
b. more resistant to impact
c. more resistant to surface scratching
d. impossible to break - .....ANSWER ...✔✔ b. more
resistant to impact
A slab-off lens is for the correction of:
a. astigmatic errors
b. excessive weight of lens
c. excessive prism imbalance at the reading level
d. exotropia - .....ANSWER ...✔✔ c. excessive prism
imbalance at the reading level
Chem-tempering makes a glass lens more impact
resistant by placing the lens in a potassium nitrate bath.
The lens undergoes a process known as:
a. ion exchange
b. iron oxide activation
c. silver halide transfer
d. thermal bleaching - .....ANSWER ...✔✔ a. ion
exchange
