A refracting telescope is an optical instrument that uses lenses to gather and focus light. The primary lens, called the objective lens, collects light from distant objects and brings it to a focus, creating a clear image. This image is then magnified by a smaller lens called the eyepiece, allowing the viewer to see details of celestial bodies like stars and planets. Refracting telescopes were historically significant in astronomy, with early models developed by Galileo Galilei and Johannes Kepler. They are known for their ability to produce sharp images, but they can be limited by lens size and chromatic aberration, which causes color distortion.