To focus on a distant object, the ciliary muscle of the eye______

Step 1: Analyze the question The question asks what happens to the ciliary muscle and the lens when the eye focuses on a distant object.

Step 2: The concept (accommodation) Accommodation is the eye's ability to change the shape of the lens to focus light on the retina. It depends on the ciliary muscle and the suspensory ligaments.

• Distant object: The light rays are nearly parallel and need little bending. The lens must be thin (less convex). The ciliary muscle relaxes, the suspensory ligaments become taut (pulled tight), and the lens is pulled flat, so it gets thinner.
• Near object: The light rays are diverging and need more bending. The lens must be thick (more convex). The ciliary muscle contracts, the suspensory ligaments become slack, and the lens becomes thicker because of its natural elasticity.

Step 3: Apply to the options

• A. Contracts, lens thicker: this is focusing on a near object. ✗
• B. Relaxes, lens thinner: this matches focusing on a distant object. ✓
• C. Contracts, lens thinner: this is not a real combination. ✗
• D. Relaxes, lens thicker: this is not a real combination. ✗

Step 4: Answer

Tip: Remember "Far = Flat". For a far object, the ciliary muscle is relaxed, the ligaments are tight, and the lens is flat (thin). For a near object, everything is the opposite: the muscle contracts, the ligaments are loose, and the lens is fat (thick).