Other forms: refractors
A refractor is a kind of lens that bends light to form a focused image. A telescope that uses this type of lens to bring distant objects into view is also known as a refractor.
The word refractor comes from refract, "to break or bend the natural course." In the case of a telescope, it's light that's being refracted, or bent, as it passes through a lens. A second lens magnifies the image, making it possible to see distant stars and planets. Today, most large telescopes used by astronomers to see very distant objects are reflecting telescopes that use mirrors rather than refractors.