"One doesn't discover new lands without losing sight of the shore."
Optics is the study of the behavior of light. In Civilization IV, the optics technology refers specifically to the branch of optics that concentrates upon improving human sight through the creation of optical instruments such as eyeglasses, telescopes and microscopes. Advancements in optics had profound effects upon man's interaction with the world around him.
It is not certain when the first working telescope was created. A number of lens-shaped crystals were found in a Viking grave dating from the 10th century, but there is debate over whether these were purely decorative or were used to enhance vision. In 1609 Galileo created a "telescopium," which he used to study the stars. Accurate star charts allowed sailors to better chart their courses while at sea.
The Janssens, a family of Dutch spectacle makers, are claimed to have built the first working microscope in 1590 but once again, there is debate over that claim. And once again, Galileo is another candidate, credited with constructing his occhiolino in 1609. Anton van Leeuwenhoek famously used an early microscope to examine cells, bacteria, and other extremely small living creatures. This research was to revolutionize man`s understanding of biology and medicine.