However, this was not public knowledge till much later. Galileo and Kepler were aware of each other's work. Galileo, however, was not strongly influenced by Kepler. The use of lenses for building a telescope was applied in Holland in 1608, though lenses had been in use for spectacles since the 13 th century. The telescope aided the eye in two ways it collected more light and provided better resolution.
Resolution is the ability to separate objects very close together.
Galileo constructed telescopes that varied in magnification power from 3 to 20 and it was the latter one that he used to turn to the heavens. Galileo was the first person to systematically record and publish his telescope observations, but not necessary the first to observe the heavens with a telescope. That there was yet much to learn. God had not revealed everything about the universe to the naked eye. The Moon and planets, and the Sun, were not the perfect crystalline spheres imaged.