Before the telescope was made people were having trouble seeing when they got older. The solution was to make glasses. The art they used to make glasses transfered to the telescope.
In about 1450 people had found out the correct "Ingredients" to make the telescope. After it was made the armies would use them to spy on their enemies. It was created by Galileo. Without the telescope they would not have been able to prepare for battle so quickly. It was a huge part of the scientific revolution.
Today we use telescopes to view other planets. We hve learned so much from them. It has surely changed the world.