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Question
What is meant by optical illusion? Give one example.
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Solution
An optical illusion is the life-like continuous movement on the screen. Television is an example of optical illusion, where the scanning beam of a picture frame of the TV camera moves so rapidly on the viewing screen of the TV set that our eyes cannot keep pace with it.
RELATED QUESTIONS
Given below is a diagram showing a defect of human eye. Study it and answer the following questions.

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Give Technical Term:
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Observe the figure whether it is correct or not and explain the phenomenon.

Match the following:
| Column - I | Column - II |
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| 3. Ciliary muscles | c. near point moves away |
| 4. Myopia | d. Screen of the eye |
| 5. Hypermetropia | e. Power of accommodation |
