NAO VOLUME 3 Exam Question &
Answers 2026
The correct transposed RX for -1.00-.50x37 is? -
CORRECT ANSWERS ✔✔-1.50 + 0.50 x 127
The correct transposition for +2.00 -2.00 x 060 is? -
CORRECT ANSWERS ✔✔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: - CORRECT ANSWERS ✔✔60 mm
A +3.00 sphere lens has a front base curve of +6.25.
What is the back surface curve? - CORRECT ANSWERS
✔✔-3.25
A -2.00 -1.00 x 045 lens has a front base curve of +6.25.
What are the back surface curves? - CORRECT
ANSWERS ✔✔-8.25 -1.00
Moving the optical center of a plus lens inward from the
correct PD results in _____ - CORRECT ANSWERS
✔✔Base in prism
Where will the optical center appear in a lensometer
when neutralizing a left lens for base in prism? -
,NAO VOLUME 3 Exam Question &
Answers 2026
CORRECT ANSWERS ✔✔To the left of the target
center
Glazing is a term used to indicate _____ - CORRECT
ANSWERS ✔✔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: - CORRECT ANSWERS ✔✔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: - CORRECT
ANSWERS ✔✔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 : -
CORRECT ANSWERS ✔✔not possible
, NAO VOLUME 3 Exam Question &
Answers 2026
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 - CORRECT ANSWERS
✔✔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 - CORRECT ANSWERS ✔✔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 - CORRECT ANSWERS
✔✔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
Answers 2026
The correct transposed RX for -1.00-.50x37 is? -
CORRECT ANSWERS ✔✔-1.50 + 0.50 x 127
The correct transposition for +2.00 -2.00 x 060 is? -
CORRECT ANSWERS ✔✔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: - CORRECT ANSWERS ✔✔60 mm
A +3.00 sphere lens has a front base curve of +6.25.
What is the back surface curve? - CORRECT ANSWERS
✔✔-3.25
A -2.00 -1.00 x 045 lens has a front base curve of +6.25.
What are the back surface curves? - CORRECT
ANSWERS ✔✔-8.25 -1.00
Moving the optical center of a plus lens inward from the
correct PD results in _____ - CORRECT ANSWERS
✔✔Base in prism
Where will the optical center appear in a lensometer
when neutralizing a left lens for base in prism? -
,NAO VOLUME 3 Exam Question &
Answers 2026
CORRECT ANSWERS ✔✔To the left of the target
center
Glazing is a term used to indicate _____ - CORRECT
ANSWERS ✔✔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: - CORRECT ANSWERS ✔✔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: - CORRECT
ANSWERS ✔✔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 : -
CORRECT ANSWERS ✔✔not possible
, NAO VOLUME 3 Exam Question &
Answers 2026
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 - CORRECT ANSWERS
✔✔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 - CORRECT ANSWERS ✔✔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 - CORRECT ANSWERS
✔✔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
