A person can read a book at 30 cm but cannot read it at 25 cm. The defect is:

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: syllabus Science Ch 11 'Human Eye and the Colourful World'_