The field of eye care—optometrists, ophthalmologists, students, and resi­ dents alike—will benefit from this outstanding book, which provides a com­ prehensive, detailed description of the current state of ophthalmic diagnostics. The book is extraordinarily well organized, enabling the eye care practitio­ ners to access the information they need for a specific patient. Likewise, the new student can start at the beginning and move through to the most current technology that makes our jobs as eye doctors easier.

Superbly curated by Drs. Taraprasad Das and PremNandhini Satgunam, the authors, have obviously worked hard on their state-of-the-art contribu­ tions. The effort and care taken by the many contributing authors is evident on every page. All are to be congratulated for the important contribution to the ophthalmic literature.

First, the book’s chapters cover the traditional components of the eye examination, starting with the basics of assessing vision and refractive error. The reader will be able to extend the information on how to measure a patient’s most fundamental visual function, blur, into the art of prescribing eyeglasses and optical dispensing.

The reader can then learn (or refresh their memory) on quantifying the binocular vision system, pupillary reactions, visual field, and colour vision.

And then the true, novel value of this textbook emerges. Chapters on the most current technology that enhances our ability to perform eye examinations are included. They cover smartphone-based imaging, cataract grading and imaging, microperimetry, and adaptive optics. The chapter on optical coher­ ence tomography will be particularly valuable to the new student or resident.

As dean of The Ohio State University College of Optometry in Columbus, Ohio, United States, I calculated the number of eye examinations one cohort of optometry students will perform during their careers. If I conservatively figure the average optometrist practices for 30 years and sees 10 patients per day, 240 working days each year, a cohort of 70 graduating optometrists will be entrusted with 5,040,000 pairs of eyes!

I anticipate this book will be consulted early in students’ and residents’ careers and often when they enter eye care practice and continue to examine those five million patients. In the end, their patients will be the real beneficia­ ries of these authors’ hard work.

Dean and Glenn A. Fry Professor in

Karla Zadnik

Optometry and Physiological Optics

The Ohio State University College of Optometry

Columbus, OH, USA

Interim Dean

The Ohio State University College of Public Health

Columbus, OH, USA

With the advent of technology, “time flies” at speed, sometimes even faster than light.

Just within the lifetime of three generations, we have seen how clunky telephones that were once only found in the houses of the elite are now sleek devices that are owned by almost everyone. Every single profession has been touched and turned around, sometimes even upside down, by these changing waves of technology.

Health care, including eye care, is no exception to this. Many instruments have become obsolete and outdated, and some have disappeared into obliv­ ion. Yet, some are indispensable and have stood the test of time, showing that old is indeed gold.

The world has become smarter, often due to the “smart gadgets” in most people’s hands in the form of phones. With this mini-computer called the smartphone, one can do wonders. Many Apps have been developed for vari­ ous tests that were once expensive and found exclusively within the sancto­ rum of big institutes. These technologies have broken barriers, blurred borders, and provided even private practitioners in rural settings with advanced diagnostic tools. While some of these smart devices and Apps may not stand the test of time, some are robust and would evolve into better, faster, and more importantly, more accurate versions. Although the choices available are sometimes overwhelmingly many, a little research can often identify the correct smart tools and instruments to suit one’s needs.

Given the drastic changes and many choices in diagnostic tools available today, a compilation of information on new and old diagnostic tools must be created. Such a compilation can help clinical practitioners to remain updated and avoid becoming outdated in their clinical practice. Within the clinical practice of eye care, which includes optometry, ophthalmology, and opti­ cianry, the most rapid changes occur in the area of diagnostics. It is an area where tools, devices, instruments, and newer techniques keep evolving to improve eye care practices.

Therefore, consolidating all this information into a comprehensive book is a real need. In fact, as a ready, go-to handbook, it will be of immense help to any student, clinician, or researcher in eye care. This is the prime motivation for putting this book together.

Although some commercial product names are mentioned in this book, the editors (and authors) are not endorsing or promoting any product. Since some of the descriptions of the techniques are drawn from the individual author’s scope of practice, we are hopeful that the diverse and global cast of authors will provide a plethora of viewpoints that will be valuable to anyone involved in eye care anywhere in the world xiv

Preface

We are immensely grateful to these contributing authors, who took the time to share their wisdom and clinical pearls with us. Additionally, we also thank the science editor, Anusha Krishnan, PhD, and the content editor, Ms. Neerja Padmanabhan, from Springer Nature, for their help.

The book title reads Technology, Techniques, and Clinical Application. The aspirational goals of this book are to briefly explain the scientific prin­ ciples of various diagnostic tools and techniques, provide an easy-to-follow protocol to execute specific techniques, and explain the clinical applications of these techniques. In essence, this book attempts to fill the “why” gaps in “what we do” in ophthalmic diagnosis wherever possible. We have also included information on newer tools, innovations, and techniques. In addi­ tion, the sequence of chapters in this book follows the sequence of clinical tests that are normally followed during an eye examination. However, very specialized or sophisticated techniques have not been included. Instead, this book focuses on generalized and commonly used techniques. We have also included a section on tele-eye health, as the SARS CoV 2 pandemic has taught us that this form of service delivery is not only possible but could also encourage eye care-seeking behaviour in rural areas; in addition, we feel that tele-eye health can and will change the future of eye care delivery. As we write this, we feel that all of us in the eye care sector must rise to face the challenges of the future, where eye care can be accessed with a click of a but­ ton or a swipe of a finger. We need to be ready.

This book is written with the desire to keep pace with the changing times. Although we are aware that many of the techniques documented in this book may become outdated shortly, we believe that this book will still be useful to eye care practitioners everywhere. Although every chapter provides a histori­ cal perspective on the techniques and instruments discussed in it, the question of whether this book describes the history of the eventual past or educates us on the practice of the future is something only time can tell.

However, one must start somewhere to ride the wave of development for better eye care.

We hope that the readers of this book enjoy this ride!

Hyderabad, Telangana, India

Hyderabad, Telangana, India

PremNandhini Satgunam