Generated by claude-sonnet-4-6 · 2026-06-15 06:51 · grounding rag
Model Answer
(i) To see nearby objects, the ciliary muscles contract, increasing the curvature (and thus the converging power) of the eye lens. This decreases the focal length of the lens, allowing a sharp image to be formed on the retina.
(ii) The power of accommodation of a normal human eye is approximately 4 dioptres. The near point is 25 cm and the far point is infinity.
Explanation
- For (i), examiners expect mention of: ciliary muscles contracting → increased curvature → decreased focal length → clear image on retina.
- For (ii), the standard value is ~4 D (some texts state the range as 0 to 4 D). Mentioning near point (25 cm) and far point (infinity) adds completeness.
- Note: The source passages provided are from unrelated chapters; this answer is based on standard NCERT Class 10 Science Chapter 11 (Human Eye) content, as the question clearly belongs there.