NAO VOLUME 3 (ANSWERED) CORRECTLY &
GRADED A+
The correct transposed RX for -1.00-.50x37 is? - ANSWER -1.50 + 0.50 x 127
The correct transposition for +2.00 -2.00 x 060 is? - ANSWER Plano +2.00 x 150
An uncut lens must be at least _______ mm in diameter to allow the edging of a 54
mm round lens decentered 3 mm in: - ANSWER 60 mm
A +3.00 sphere lens has a front base curve of +6.25. What is the back surface
curve? - ANSWER -3.25
A -2.00 -1.00 x 045 lens has a front base curve of +6.25. What are the back surface
curves? - ANSWER -8.25 -1.00
Moving the optical center of a plus lens inward from the correct PD results in _____ -
ANSWER Base in prism
Where will the optical center appear in a lensometer when neutralizing a left lens for
base in prism? - ANSWER To the left of the target center
Glazing is a term used to indicate _____ - ANSWER A defect that occurs when an
anti-reflective lens is tinted
Frequently, bicentric grinding (slab-off) is used as a means of obtaining prism in the
reading field to correct induced prism imbalance. The usual correction during the
fabrication process is achieved by grinding prism in the following direction: -
ANSWER up
A patient stops in to see you for adjustment of his glasses. After careful inspection
you find the only thing wrong that there is too much pantoscopic tilt. To make the
necessary adjustment you will: - ANSWER Angle the temples upward from the end
pieces
If the RX is +2.00 -4.00 x 135, it would be necessary to decenter the lens _____to
create 1.00 prism base in : - ANSWER not possible
Rewrite the RX below, which is prescribed for a patient afflicted with double vision,
so as to make better balanced lenses:
OD -1.00 -0.50 x 090 5.00 BU
OS -1.25 - 0.50 x 090 1.00 BD - ANSWER OD -1.00 -0.50 x 090 3.00 prism BU
OS -1.25 -0.50x 090 3.00 prism BD
Correct the imbalance in the following prescription by use of slab-off. Reading level
is 10 mm:
OD +5.00 -2.00 x 090
, OS +2.25 -3.00 x 090 - ANSWER 2.25 prism BU in OS
You are fitting a patient with a stock frame, 24 DBL, 44 eve size and 137 mm skull
temples. The distance PD is only 62 mm. If by some unfortunate error the lenses are
not decentered at all, how much prism is created in each eye?
RX: OU -2.25 -1.50 x 045 - ANSWER 0.5 prism BI
A situation where the frame front is somewhat twisted, with the planes of the two
lenses being out of line with one another, is called: - ANSWER Skewed bridge
When a frame is said to have a parabolic curve (or positive face form), the following
condition is meant: - ANSWER The bridge of the frame is out further than then end
pieces
If the lenses of a patient wearing -8.00 spheres are brought closer or his/her eyes,
what if any effect will this have on the lenses? - ANSWER Increase minus power
effect
Slab-off is ground on the lens that has the _____in the 090 meridian: - ANSWER
Weaker plus
Which of the following areas is not a factor in determining vertical imbalance? -
ANSWER Add power
A lens dispersing white light into its component colors is an example of : - ANSWER
Chromatic aberration
The lens aberration that produces a shorter focal length for rays near the edge of the
lens than rays near the optical axis is called: - ANSWER Spherical aberration
The aberration affecting image shape when wearing high minus lenses is called: -
ANSWER barrel distortion
What type of prismatic effect is easiest to tolerate at the near point? - ANSWER
Base in
You can eliminate the effects of pantoscopic angle by: - ANSWER Raising the
optical center by 1/2 the amount of tilt
1 base up ad 2 base in for a left eye would be found in which quadrant? - ANSWER
II
2 base down and 2 base out for left eye would be found in which quadrant? -
ANSWER IV
3 base out and 5 base down for a right eye would be found in which quadrant? -
ANSWER III
3 base down and 2 base in for a left eye would be found in which quadrant? -
ANSWER I
GRADED A+
The correct transposed RX for -1.00-.50x37 is? - ANSWER -1.50 + 0.50 x 127
The correct transposition for +2.00 -2.00 x 060 is? - ANSWER Plano +2.00 x 150
An uncut lens must be at least _______ mm in diameter to allow the edging of a 54
mm round lens decentered 3 mm in: - ANSWER 60 mm
A +3.00 sphere lens has a front base curve of +6.25. What is the back surface
curve? - ANSWER -3.25
A -2.00 -1.00 x 045 lens has a front base curve of +6.25. What are the back surface
curves? - ANSWER -8.25 -1.00
Moving the optical center of a plus lens inward from the correct PD results in _____ -
ANSWER Base in prism
Where will the optical center appear in a lensometer when neutralizing a left lens for
base in prism? - ANSWER To the left of the target center
Glazing is a term used to indicate _____ - ANSWER A defect that occurs when an
anti-reflective lens is tinted
Frequently, bicentric grinding (slab-off) is used as a means of obtaining prism in the
reading field to correct induced prism imbalance. The usual correction during the
fabrication process is achieved by grinding prism in the following direction: -
ANSWER up
A patient stops in to see you for adjustment of his glasses. After careful inspection
you find the only thing wrong that there is too much pantoscopic tilt. To make the
necessary adjustment you will: - ANSWER Angle the temples upward from the end
pieces
If the RX is +2.00 -4.00 x 135, it would be necessary to decenter the lens _____to
create 1.00 prism base in : - ANSWER not possible
Rewrite the RX below, which is prescribed for a patient afflicted with double vision,
so as to make better balanced lenses:
OD -1.00 -0.50 x 090 5.00 BU
OS -1.25 - 0.50 x 090 1.00 BD - ANSWER OD -1.00 -0.50 x 090 3.00 prism BU
OS -1.25 -0.50x 090 3.00 prism BD
Correct the imbalance in the following prescription by use of slab-off. Reading level
is 10 mm:
OD +5.00 -2.00 x 090
, OS +2.25 -3.00 x 090 - ANSWER 2.25 prism BU in OS
You are fitting a patient with a stock frame, 24 DBL, 44 eve size and 137 mm skull
temples. The distance PD is only 62 mm. If by some unfortunate error the lenses are
not decentered at all, how much prism is created in each eye?
RX: OU -2.25 -1.50 x 045 - ANSWER 0.5 prism BI
A situation where the frame front is somewhat twisted, with the planes of the two
lenses being out of line with one another, is called: - ANSWER Skewed bridge
When a frame is said to have a parabolic curve (or positive face form), the following
condition is meant: - ANSWER The bridge of the frame is out further than then end
pieces
If the lenses of a patient wearing -8.00 spheres are brought closer or his/her eyes,
what if any effect will this have on the lenses? - ANSWER Increase minus power
effect
Slab-off is ground on the lens that has the _____in the 090 meridian: - ANSWER
Weaker plus
Which of the following areas is not a factor in determining vertical imbalance? -
ANSWER Add power
A lens dispersing white light into its component colors is an example of : - ANSWER
Chromatic aberration
The lens aberration that produces a shorter focal length for rays near the edge of the
lens than rays near the optical axis is called: - ANSWER Spherical aberration
The aberration affecting image shape when wearing high minus lenses is called: -
ANSWER barrel distortion
What type of prismatic effect is easiest to tolerate at the near point? - ANSWER
Base in
You can eliminate the effects of pantoscopic angle by: - ANSWER Raising the
optical center by 1/2 the amount of tilt
1 base up ad 2 base in for a left eye would be found in which quadrant? - ANSWER
II
2 base down and 2 base out for left eye would be found in which quadrant? -
ANSWER IV
3 base out and 5 base down for a right eye would be found in which quadrant? -
ANSWER III
3 base down and 2 base in for a left eye would be found in which quadrant? -
ANSWER I
