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.

An amphoteric oxide is a type of oxide that can act as both an acid and a base. This means it can react with both acids and bases, either accepting or donating protons (H⁺ ions) depending on the pH of the solution. Amphoteric oxides exhibit this dual behavior because they have both acidic and basic properties. Aluminum oxide (Al₂O₃) and zinc oxide (ZnO) are examples of common amphoteric oxides.

A concave mirror is used in a solar cooker. Specifically, a concave mirror focuses sunlight onto a small area, increasing the intensity of the sunlight and generating heat. This concentrated sunlight is then used for cooking in solar cookers, harnessing solar energy for practical applications.