The correct statement for close vision focusing is:
- The ciliary muscle contracts. This tightens the ciliary zonule and allows the lens to bulge.
Explanation:
1. When focusing on close objects, the ciliary muscle contracts.
2. The contraction of the ciliary muscle tightens the ciliary zonule (suspensory ligaments).
3. The tightening of the ciliary zonule reduces tension on the lens, allowing it to become more rounded or bulged.
4. This change in lens shape helps in refracting light properly onto the retina for clear close vision.
This process is known as accommodation, where the lens adjusts its shape to focus on objects at different distances.
