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A person can read a book at 30 cm but cannot read it at 25 cm. The defect is:
AMyopia
BCataract
CAstigmatism
DHypermetropia
Answer & Solution
Correct answer: D. Hypermetropia
1. A normal eye can read clearly at 25 cm or farther.
2. A person who needs 30 cm clearly cannot focus closer than that.
3. So the near point has shifted farther from the eye.
4. This is hypermetropia (long-sightedness).
5. Hence a convex lens is needed to correct it.
_Source: NCERT Class 10 Science Ch 11 'Human Eye and the Colourful World'_
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