When you look at an object very close to your eyes, the:

As stated in the NCERT text (Section 10.1.1, Power of Accommodation): "When you are looking at objects closer to the eye, the ciliary muscles contract. This increases the curvature of the eye lens. The eye lens then becomes thicker. Consequently, the focal length of the eye lens decreases. This enables us to see nearby objects clearly."

So for a very close object:

• Ciliary muscles contract (not relax).
• The curvature of the eye lens increases, so the lens becomes thicker (not thinner).
• Because a thicker, more curved lens has a shorter focal length, the image of the nearby object can still be focused precisely on the retina.

This adjustment ability is called the eye's power of accommodation.

Why each option is right/wrong:

• (A) Correct. Ciliary muscles contract, increasing lens curvature, making the lens thick — exactly what the text describes for viewing very close objects.
• (B) Incorrect. This describes what happens when viewing distant objects: "When the muscles are relaxed, the lens becomes thin." It is the reverse of what happens for near objects.
• (C) Incorrect. The muscles do contract for a close object, but the text explicitly states the lens becomes thicker (increased curvature), not thinner.
• (D) Incorrect. This combines the relaxed-muscle condition (for distant vision) with a thin lens, which is unrelated to viewing a very close object.