The coordination and editing of this book on Presbyopia was a challenge launched by the Portuguese Society of Ophthalmology (SPO) Board and its President, Prof. Monteiro Grillo, the invitation and trust of whom I thank in advance.

Presbyopia is undoubtedly a fundamental area of Ophthalmology in the 21^st century. The treatment of presbyopia is the last frontier of refractive surgery with a high impact, given the increase in its projected prevalence in the future, with a 100% incidence in a demographic inverted pyramid. There is also a greater visual requirement at different working distances, in an increasingly active population up to more advanced ages. However, we still do not know much about its pathophysiology and despite great therapeutic advances in recent years, we still cannot imitate the capacity for accommodation that Nature conceived over millions of years of evolution.

Due to its relevance, and the need to follow the technological development and the multiple aspects still under open discussion, I accepted this challenge as an excellent instrument of knowledge sharing in this area, which we want to be as wide as possible.

Thus this project was the ideal opportunity, to promote at the ESCRS Lisbon meeting the Luso-Hispanic-Brazilian Symposium on the Treatment of Presbyopia, which was the basis for the preparation of this book. It was a way to return to a pre-existing idea, to bring together the implant-refractive groups of CIRP, SECOIR and BRASCRS, which have already so much in common, and that can be further enhanced.

In this international sharing, it was our intention that the chapters were articles of opinion of the authors, faithful to the language of each one, so we decided to keep the originals. After all, and despite the linguistic differences, the capacity for understanding among all of us is easy because we all speak the same language: that of science.

To all who participated in this book, my deepest and most sincere thanks. Thank you for accepting the challenge. Thank you for sharing Your knowledge, Your experience, Your specialty, Your opinion.

A very special thanks to Théa laboratories for making this Monograph possible and thus stimulating the sharing of knowledge in the SPO.

We hope that this book will fulfill three objectives:

• Be the trigger for subsequent projects that integrate the three aforementioned groups
• Highlight the discussion on this subject and bring us greater knowledge as to improve our therapeutic capacity
• Let us continue to evaluate the impact of the treatment of presbyopia