AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
When shifting gaze from a distant tree to a nearby book, the ciliary muscles contract, increasing the curvature of the eye lens. The lens becomes thicker, and its focal length decreases, allowing the eye to focus the nearby object clearly on the retina. It is the ciliary muscles that bring about this change.
Source: Chapter 10, Section 10.1.1 Power of Accommodation
---
The examiner expects two things for 2 marks: (1) the change in the lens — becomes thicker/more curved, focal length decreases; (2) the structure responsible — ciliary muscles (contract). Avoid vague terms like "the eye adjusts"; be specific. The word "accommodation" can be used as a bonus term but is not compulsory here.