Accommodation in the eye lens is the process of adjusting its shape to focus on objects at different distances. This adjustment is controlled by the ciliary muscles. When focusing on nearby objects, these muscles contract, thickening the lens. For distant objects, the muscles relax, flattening the lens, ensuring clear vision at varying distances.

Calcium is the element that is present in both cement and bones. In cement, calcium is a key component of calcium silicate compounds, which contribute to the strength and durability of the material. In bones, calcium is a vital mineral that provides structural support and strength. It plays a crucial role in various physiological processes in the human body, including muscle function and nerve signaling.