Johannes Gutenberg's printing press created a surge in demand for spectacles, as the new practice of reading made Europeans across the continent suddenly realize that they were farsighted; the market demand for spectacles encouraged a growing number of people to produce and experiment with lenses, which led to the invention of the microscope, which shortly thereafter enabled us to perceive that our bodies were made up of microscopic cells. You wouldn't think that printing technology would have anything to do with the expansion of our vision down to the cellular scale, just as you wouldn't have thought that the evolution of pollen would alter the design of a hummingbird's wing. But that is the way change happens.