Biomedical Engineering Reference
In-Depth Information
5. (a) The vertical meridian of the lens has a power of
+
4.00 D and the horizon-
tal meridian has a power of
6.00 D. Horizontally diverging object rays are
focused by the stronger horizontal meridian to form a vertical line. The
line is located at
+
′
=
L
L
+
F
(100)(1.00)
−
⎡
⎥
⎤
⎥
L
′
=
+
6.00 D
40.00 cm
′
=
+
L
3.50 D
1
l
′
L
=
′
(100)(1.00)
l
′
=
+
3.50 D
′
=
+
l
28.57 cm
(b) Vertically diverging rays are focused by the weaker vertical lens meridian
to form a horizontal line. The line is located at
′
=
L
L
+
F
(100)(1.00)
−
⎡
⎥
⎤
⎥
′
=
L
+
4.00 D
40.00 cm
′
=
+
L
1.50 D
1
l
′
L
=
′
(100)(1.00)
l
=
+
1.50 D
′
′
=
+
l
66.67 cm
(c) 66.67
−
28.57 cm
=
38.10 cm
(d)
3.50 D
+
1.50 D
=
2.50 D
2
Therefore, the circle of least confusion is located 40.00 cm to the right of
the lens.
6. (a)
−
4.00
+
14.00
×
180;
+
10.00
−
14.00
×
090
(b) pl
+
10.00
×
180;
+
10.00
−
10.00
×
090
(c)
+
5.00
−
8.00
×
180;
−
3.00
+
8.00
×
090
(d)
−
6.00
+
8.00
×
180;
+
2.00
−
8.00
×
090
7. (a) Against-the-rule compound hyperopic.
(b) With-the-rule compound myopic astigmatism.
(c) With-the-rule mixed astigmatism.
