Science — CBSE Class 10 board question

Power of Accommodation: The ability of the eye lens to adjust its focal length to see objects clearly at different distances is called the power of accommodation.

Image distance: The image distance in the eye remains constant (image always forms on the retina). When the object distance increases, the eye lens adjusts its focal length so that the image is still formed on the retina.

Part responsible — Ciliary Muscles: When the distance of an object increases, the ciliary muscles relax, causing the eye lens to become thinner. This increases the focal length of the lens, allowing the distant object to be focused clearly on the retina.

Source: Chapter 10, Section 10.1.1 – Power of Accommodation

---

• Examiners expect three clear parts: definition, image distance behaviour, and explanation of ciliary muscles' role.
• A common mistake is saying image distance changes — it does NOT; it stays fixed at the retina. The focal length changes instead.
• Use key terms: relax, thinner, focal length increases — these fetch marks directly.