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OCULAR ACCOMMODATION
(P 35 01)

Apparatus:
GSN 246
POG 465
POG 462
POG 251
POG 240.02
KAL 60/5A

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Adhesive magnetic
Ray box, 6V 20 W
Diaphragm 3 and 5
Semicircle, lens
Plan-convex, lens
Connecting lead
Power supply
Whiteboard marker
Ruler

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1
1
2
1
1
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The lamp with the diaphragm inserted is placed near the left-hand edge of the
panel, arranging it so that the middle light ray is projected horizontally across
the panel. This ray serves as the optical axis and is drawn in. The pin in the
lamp is pulled out, creating three divergent rays of light.
The semi-circular object serving as a convex lens is placed at a distance of 33
cm from the light and symmetrical to the optical axis.

The light source symbolizes an object point and the semi-circular object the eye
lens. The eye lens focuses the light rays at focal point F, symbolizing the eye's
"yellow spot".
The "model of the eye" is drawn in. At the position shown the eye sees the
object sharply.

The light is moved toward the model of the eye, thus decreasing the object
distance. Instead of seeing a sharp image point, a light spot on the retina
results and the eye perceives the object unclearly since its image is not
focused.

Optics Panel Type |

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In a case like this the eye increases its power of refraction by increasing the
curvature of the lens. In the experiment this is simulated by adding the
planoconvex lens. The object is once again projected onto the retina sharply.

| Optics Panel Type


FAULTY VISION AND ITS CORRECTION –
NEAR-SIGHTEDNESS
(P 35 02)

Apparatus:
GSN 246
POG 465
POG 462
POG 251
KAL

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Adhesive magnetic

Ray box, 6V 20 W
Diaphragm 3 and 5 slits
Semicircle, lens model
Connecting lead
Power supply
Whiteboard marker
Ruler

1
2
2
1
4
1
1
1

First, an optical axis is drawn in.
Two lights with diaphragms having slits are arranged symmetrical to the axis as
shown in the diagram. A total of six light rays parallel to the axis are generated.
The semi-circular object serving as the eye lens is placed at a distance of 30 cm
from the lamps. The light rays proceeding from a remote object are focused at
point F on the retina in the case of an eye with normal vision. The object is
sharp at this point.

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A near-sighted individual's eye is too elongated. This is symbolized in the
experiment by drawing a more sharply curved line (at a distance of about 23
cm from the eye lens as shown in the diagram). A light spot results in the place

of the image point and the near-sighted eye sees only a blurred object.

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This faulty vision is corrected by eyeglasses consisting of concave lenses. In the
experiment this is symbolized by placing a planoconcave lens in front of the
model of the eye as shown in the diagram. The planoconcave lens disperses

Optics Panel Type |

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somewhat the light rays which travel almost parallel to the axis. The lens
system consisting of a concave lens and the eye lens corrects the position of
the image point so that it is projected upon the retina.

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| Optics Panel Type


FAULTY VISION AND ITS CORRECTION –
FAR-SIGHTEDNESS
(P 35 03)

Apparatus:
GSN 246
POG 465
POG 462

POG 251
KAL

Adhesive magnetic board
Ray box, 6V 20 W
Diaphragm 3 and 5 slits
Semicircle, lens model
Connecting lead
Power supply
Whiteboard marker
Ruler

1
1
1
1
2
1
1
1

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The light is equipped with a diaphragm with three slits and placed near the
left-hand edge of the panel so that the middle light ray is projected across the
panel horizontally. This serves as the optical axis. The semi-circular model
representing the eye lens is placed 26 cm from the lamp. The divergent light
rays proceeding from the object point are focused at image point F located on
the eye's retina. The eye possessing normal vision is drawn in.

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As compared with the eye having normal vision, a far-sighted eye is too short. A
model of a far-sighted eye is drawn in as shown in the diagram. The object
point is not projected sharply onto the retina, but rather as a light spot.

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Applying a convex lens as an eyeglass increases the power of refraction of the
lens system consisting of eyeglass and eye.
In the experiment this is simulated by placing a planoconvex lens directly in
front of the semi-circular model.
The object is now projected onto the retina as a precise image point.

Optics Panel Type |

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| Optics Panel Type