Refracting telescope. Computer artwork showing the structure of a typical refracting telescope. A refracting telescope is a type of optical telescope that uses a lens as its objective to form an image. Nowadays, this kind of telescope is mainly used in amateur astronomy. Although large refracting telescopes were very popular in the second half of the 19th century, for most research purposes the refracting telescope has been superseded by the reflecting telescope, which allows larger apertures.