Final answer:
The process by which the ciliary muscles contract to change the shape of the lens for proper focus of light on the retina is known as accommodation, crucial for maintaining clear vision at varying distances.
Step-by-step explanation:
The phenomenon where the ciliary muscles contract, pulling on the suspensory ligaments and changing the shape of the lens to focus light properly on the retina, is known as accommodation. This process allows for clear vision whether we are looking at objects that are close or far away by changing the lens's focal length. As we age, the ability for accommodation can diminish, often leading to the need for corrective lenses.
Ability for accommodation changes with age; this loss of elasticity in the lens, which makes it difficult to focus on nearby objects, is corrected through the use of converging lenses. In contrast, when the eye is viewing distant objects, it is in a relaxed state, termed as totally relaxed vision; whereas, when viewing near objects, the lens must become more converging (more powerful) which is an accommodated state.