Lenses

A lens is a piece of transparent material that is used to refract light in order to focus or diverge it. Lenses are commonly used in optical instruments, such as cameras, telescopes, and microscopes, to control the way that light is transmitted and to produce an image of an object. Lenses are available in a wide variety of shapes and sizes, and can be made from different materials, such as glass, plastic, or crystal, depending on the specific application. The properties of a lens, such as its focal length, index of refraction, and aperture, determine how it will behave when light passes through it.