Ординатура / Офтальмология / Английские материалы / Essentials of Ophthalmic Lens Finishing, 2nd edition_Brooks_2003
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K E Y S E R I E S 1
Single Vision Lenses
1.(a) To the right.
(b) Viewed from the front, the cross should be 3 mm to the left of the center spot.
2.2 mm in. Viewed from the front, the marked cross should be 2 mm to the right of the center dot.
3.The decentration per lens is 1.5 mm. When viewed from the front, the center dot is to the right of the marked cross.
4.1.5 mm in To the left
5.2.0 mm in To the right
6.0 mm
They are at the same location.
7.4.5 mm in To the left
8.3 mm in To the right
9.3.5 mm in To the right
10.1 mm out To the right
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K E Y S E R I E S 2
Single Vision Lenses
CENTRATION FOR MONOCULAR PDS AND PRACTITIONER-
SPECIFIED MAJOR REFERENCE POINT HEIGHT
Answer Format
•R lens horizontal decentration = a
(When viewed from the front of the lens, the center lensmeter dot is a mm to the right of the marked cross.)
•L lens horizontal decentration = b
(When viewed from the front of the lens, the center lensmeter dot is b mm to the left of the marked cross.)
1.a = 5 mm b = 3 mm
2.a = 7 mm b = 8 mm
3.a = 7 mm b = 5 mm
4.a = 3.5 mm b = 1.5 mm
5.a = 4 mm b = 3 mm
6.a = 3 mm b = 6 mm
7.a = 2.5 mm b = 5.5 mm
Answer Format
•R lens horizontal decentration = a R vertical decentration = b
(When viewed from the front, the center lensmeter dot is a mm to the right of and b mm above the marked cross.)
•L lens horizontal decentration = c L vertical decentration = d
(When viewed from the front, the center lensmeter dot is c mm to the left of and d mm above the marked cross.)
8.a = 3.5 mm
b = +2 mm raise c = 3.5 mm
d = +2 mm raise
9.a = 4.5 mm
b = +3 mm raise c = 4.5 mm
d = +3 mm raise
10.a = 5.5 mm
b = +1 mm raise c = 5.5 mm
d = +1 mm raise
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11.a = 4 mm
b = +3.5 mm raise c = 3 mm
d = +3.5 mm raise
12.a = 7 mm
b = +1.25 mm raise c = 4 mm
d = +1.25 mm raise
13.a = +3 mm
b = 1.25 mm raise c = +6 mm
d = 1.25 mm raise
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K E Y S E R I E S 3
Single Vision Lenses
LENSES WITH PRESCRIBED PRISM
Answer Format
•Prism base direction is base = a.
•Horizontal decentration = b.
(When viewed from the front of the lens, the center lensmeter dot is b mm to the c of the marked cross.)
1.a = in
b = 3.5 mm c = right
2.a = out
b = 10.5 mm c = right
3.a = out
b = 1.5 mm c = left
4.a = in
b = 4 mm c = left
5.a = up
b = 4 mm c = right
6.a = up
b = 2 mm c = left
7.a = down b = 3 mm c = left
8.a = down
b = 5.5 mm c = right
Answer Format
•Prism base direction is base = a.
•Horizontal decentration = b.
(When viewed from the front of the lens, the center lensmeter dot is b mm to the c of the marked cross.)
9.a = out and down b = 3.5 mm
c = right
10.a = in and up b = 2.5 mm c = right
11.a = in and down b = 1.5 mm
c = left
12.a = out and up b = 5 mm
c = left
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Answer Format
When viewed from the front, the middle lensmeter dot is approximately a mm (above, below, to the right of, or to the left of) b the geometrical center of the lens blank. This same lensmeter dot should also be c mm to the d of the marked cross, since horizontal decentration = c mm.
13.a = 2 mm b = below c = 4 mm d = right
14.a = 2 mm b = above c = 8 mm d = right
15.a = 4 mm
b = to the right of c = 6 mm
d = right
16.a = 4 mm
b = to the left of c = 6 mm
d = right
17.a = 4 mm
b = to the right of c = 3.5
d = right
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K E Y S E R I E S 4
Progressive Addition Lenses: Using the Fitting Cross
1.Horizontal decentration
R = 4.5 mm L = 5.5 mm
Fitting cross raise:
R = +2 mm L = +2 mm
2.Horizontal decentration
R = 3 mm L = 2 mm
Fitting cross raise:
R = +2.5 mm L = +3.5 mm
3.Horizontal decentration
R = 2 mm L = 2 mm
Fitting cross raise:
R = +3.5 mm L = +3.5 mm
4.Horizontal decentration
R = 1 mm L = 3 mm
Fitting cross raise:
R = +1 mm L = +2 mm
5.Horizontal decentration
R = 1.5 mm L = 2.5 mm
Fitting cross raise:
R = +4.5 mm L = +4.5 mm
6.Horizontal decentration
R = 4.5 mm L = 4.5 mm
Fitting cross raise:
R = +3.5 mm L = +4.5 mm
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K E Y S E R I E S 5
Progressive Addition Lenses: Using Hidden ‘Circles’
1.Horizontal decentration
R = 2 mm L = 2 mm
Hidden circle raise or drop:
R = +1 mm L = +1 mm
2.Horizontal decentration
R = 1.5 mm L = 1.0 mm
Hidden circle raise or drop:
R = –1 mm L = –1 mm
3.Horizontal decentration
R = 3.5 mm L = 4.5 mm
Hidden circle raise or drop:
R = –1 mm L = 0 mm
4.Horizontal decentration
R = 1.0 mm L = 1.5 mm
Hidden circle raise or drop:
R = +2 mm L = +1 mm
5.Horizontal decentration
R = 2 mm L = 1 mm
Hidden circle raise or drop:
R = +0.5 mm L = +1.0 mm
6.Horizontal decentration
R = 1.0 mm L = 1.5 mm
Hidden circle raise or drop:
R = +0.5 mm L = +2.0 mm
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7.Horizontal decentration
R = 0.5 mm L = 2.0 mm
Hidden circle raise or drop:
R = +2.5 mm L = +3.5 mm
8.Horizontal decentration
R = 1.5 mm L = 0.5 mm
Hidden circle raise or drop:
R = +0.5 mm L = +1.5 mm
9.Horizontal decentration
R = 0.5 mm out L = 1.0 mm in
Hidden circle raise or drop:
R = –1.0 mm L = –0.5 mm
10.Horizontal decentration
R = 1.5 mm L = 2.5 mm
Hidden circle raise or drop:
R = +3.0 mm L = +2.0 mm