To assist the eye in focusing, what process allows the lens to change its curvature?

The process that allows the lens of the eye to change its curvature in order to focus on objects at varying distances is known as accommodation. Accommodation is a crucial function of the eye that involves the ciliary muscles contracting or relaxing to adjust the shape of the lens. When looking at distant objects, the lens becomes flatter, while for near objects, it becomes more rounded, increasing its focusing power. This flexibility of the lens ensures that light rays are properly focused onto the retina, allowing for clear vision at different distances.

Understanding accommodation is essential in grasping how vision works, as it illustrates the dynamic nature of the eye in responding to different visual stimuli. Other processes mentioned, such as refraction, describe the bending of light as it passes through different mediums, but do not specifically relate to the lens's ability to change shape. Convergence refers to the inward movement of the eyes as they focus on a nearby object, not the actual changing of the lens's shape. Extension is not a recognized term in this context. Therefore, accommodation is the correct term that encapsulates the lens's ability to adjust focus for clear vision.