Why did Isaac Newton develop a reflecting telescope?

Isaac Newton developed the reflecting telescope primarily to overcome the limitations of refracting telescopes, which rely on lenses to focus light.12

Refracting telescopes suffer from chromatic aberration, a form of color distortion that occurs because glass lenses bend light of different wavelengths (colors) by different amounts. This causes light to focus at slightly different points, resulting in blurred images with colored fringes.32

By using a curved mirror instead of a lens to collect and focus light, Newton’s design avoided this dispersion, as reflected light does not separate according to wavelength. In his configuration, Newton placed a small plane mirror at a 45° angle inside the telescope tube to redirect the light to an eyepiece on the side, allowing for clear, undistorted observation.12