To Experiment - Betzold 89947 Handbuch

Solution to experiment 5.2 „testing light refraction"
Several converging lenses placed in a row intensify the focusing, several diverging lenses intensify the spreading of light. If a
converging and diverging lens are combined, the effect of each lens up to parallel transiting rays of light is lessened.
Solution to experiment 5.3 "defective vision I"
1. The eye lens is an optical lens with both sides curving outwards. It is a converging lens (biconvex).
2. In this example, the focal point lies behind the retina.
3. Yes, this is considered a vision defect. The featured eye is farsighted. Objects up close are not seen clearly.
4. The focal point must be shifted further forward onto the retina for a clear vision of the object. The incoming rays of light need a
stronger focusing. This can be achieved with a converging lens.
5. Lens no. 4 is the fitting lens. Rays of light are focused correctly so that the focal point lies on the retina
6. It makes sense to wear eyeglasses. Eyeglasses are actually 2 optic lenses (glass lenses) fitted into to a frame (eyeglass
frame). In this example, the eyeglasses need converging lenses.
Keep in mind that eyeglasses can only compensate an eye defect so that a person wearing them can see clearly. They cannot
correct defects of the eye.
Solution to experiment 5.4 "defective vision II"
1. The eye lens is an optical lens with both sides curving outwards. It is a converging lens (biconvex).
2. In this example, the focal point lies in front of the retina.
3. Yes, this is considered a vision defect. The featured eye is nearsighted. Distant objects are not seen clearly.
4. The focal point must be shifted backwards onto the retina for a clear vision of the object. The incoming rays of light need less
focusing. This can be achieved with a diverging lens.
5. Lens no. 7 is the fitting lens. Rays of light are spread so that the focal point lies on the retina
6. It makes sense to wear eyeglasses. Eyeglasses are actually 2 optic lenses (glass lenses) fitted into to a frame (eyeglass
frame). In this example, the eyeglasses need diverging lenses.
Keep in mind that eyeglasses can only compensate an eye defect so that a person wearing them can see clearly. They cannot
correct defects of the eye.
24
© Arnulf Betzold GmbH