The first invention of the telescope is often credited to either Hans Lippershey or Sacharias Jansen.
Both men were Dutch eyeglass-makers that experimented with lenses to view distant objects.
By placing one lens (convex) in front of another (concave), an image of a remote object could be magnified.
In 1608, Lippershey made a patent application for his invention, which he called the "Dutch Perspective Glass". It was described as a device "for seeing far-away things as though nearby" and consisted of a pair of lenses inside a tube.
The patent application was disallowed because his invention of the telescope was not unique. It was an apparatus that would be obvious to anyone familiar with lens-making.
Galileo, the Italian physicist and mathematician, was aware of the "perspective glass" and began making improvements to its magnification.
The lens created by Lippershey was limited to 3x magnification of a remote object. Galileo realized that magnification was determined by the strength of the concave (eyepiece) lens in relation to the convex lens.
Galileo was able to create glass lenses with curvatures that had never been previously manufactured. This allowed him to make an instrument with a 32x magnification.
This new instrument was named the "telescope" from Greek tele meaning "far" and skopein meaning "to look or see".
Galileo used his invention of the telescope to discover mountains on the moon.
Isaac Newton made significant improvements to the image quality of telescopes.
The spectrum of colors in light do not bend equally through glass lenses and causes a distortion of the image.
Newton solved this problem by using mirrors to create a reflecting telescope that reduced distortion.