Presbyopia, commonly known as "old man's eye disease," is a condition that leads to difficulty seeing near objects due to changes in the eye's lens. Historical explanations date back to Aristotle, with significant contributions from figures like René Descartes and Ernst Brücke, who helped identify the ciliary muscle's role in accommodation. Benjamin Franklin devised the first bifocals in the 1780s as a solution for presbyopia. In the 19th century, advancements included the development of eye charts by Heinrich Kuechler and Eduard Jaeger for assessing near vision. Hermann von Helmholtz later explained that presbyopia results from the loss of lens elasticity due to aging.Presbyopia, an age-related decline in near vision, has driven the search for effective and convenient pharmaceutical therapies. Topical parasympathomimetic agents, particularly pilocarpine, have emerged as promising treatments for this condition. The aim of this book is to provide an understanding and an overview of presbyopia research progress.