Contact Lens Complications, 4th ed. NathanEfron. Amsterdam, The Netherlands: Elsevier Health Sciences; 2024. Print + eBook: ISBN: 978‐0‐7020‐8427‐0. $107.24.

Professor Nathan Efron is a distinguished academic whose pioneering research has shaped modern contact lens practice. His book, Contact Lens Complications, has long been regarded as a cornerstone resource in optometric education and clinical practice. Consistent with previous editions, the book presents topics in a logical, tissue-based format that aligns with the way clinicians approach ocular assessment. This structure is particularly beneficial for students, as it mirrors the systematic examination of ocular tissues performed during slit-lamp examinations. The book includes a very useful quick-find index, which serves as a clinical manual of conditions and can be used as an aide-memoir or as an excellent quick reference for teaching contact lens complications to students. Before delving into the tissues affected by contact lens wear, Professor Efron carefully describes both anterior eye examination techniques and the grading scales used to monitor changes and support accurate record keeping. The digital version of the book gives readers access to two valuable resources for assessing and enhancing grading: the Efron Grading Morphs and the Efron Grading Tutor. The latter allows users to calculate grading accuracy and compare their performance with that of experts, making it an extremely valuable interactive tool. The Efron Grading Scales are also provided in Appendix A, accompanied by a table describing the salient features of each image. This is particularly useful in educational and research settings, as printed copies of these grading scales do not contain the level of detail presented in these tables.Throughout the book, each topic is carefully explained including signs, symptoms, aetiology, pathology, treatment, prognosis, and differential diagnosis. These explanations are supported by summaries of key research, allowing readers to appreciate the evidence base behind clinical observations without being overwhelmed by technical detail. One of the key strengths of this book is the exceptional quality and quantity of clinical images and diagrams (over 650 in total!). For instance, I find the diagrams used throughout the chapters to illustrate the aetiology and pathogenesis of various complications extremely valuable, as they visually clarify complex mechanisms and make them easier to understand. I highly recommend that students engage with the clinical photographs included in each section, as they offer invaluable visual references that enhance recognition and differentiation of contact lens-related complications. In the preface, Professor Efron rightly acknowledges that, as with any area of healthcare, our clinical understanding continually evolves. Reflecting this, the fourth edition includes two new chapters on Lid Wiper Epitheliopathy and Lid-Parallel Conjunctival Folds, both of which are increasingly recognized as clinical signs associated with dry eye and contact lens discomfort. Although this edition thoughtfully incorporates findings from the TFOS DEWS II report in Chapter 9, a new consensus report, TFOS DEWS III, has recently been published, and interested readers are encouraged to consult it for the latest updates in dry eye research and management. It is worth noting that grading systems for assessing the severity of Lid Wiper Epitheliopathy, Meibomian Gland Dysfunction, and Lid-Parallel Conjunctival Folds are thoughtfully included within the relevant chapters (pages 58, 81, and 148, respectively). However, it would be helpful if these grading scales were also reproduced in a separate appendix. Including them in a consolidated format would enhance usability, allowing clinicians and students to access them quickly during clinical assessments or as a learning and revision tool. To summarize, this book is an essential read for anyone seeking to deepen their understanding of contact lens complications. An added advantage of this edition is its availability as an eBook, which can be accessed on mobile devices. This enhances the user experience by allowing quick navigation, easy content search, and convenient viewing of clinical images, making it especially useful for students and clinicians on the move.Marta Vianya-Estopa, PhD, MCOptom Anglia Ruskin University Cambridge, UKMarta obtained her MSc and PhD from the University of Bradford (UK) and is currently an Associate Professor at Anglia Ruskin University in Cambridge (UK). She previously worked in the ophthalmic and contact lens industries as well as in clinical practice. She is a Fellow of the British Contact Lens Association (BCLA) and a member of the British and Irish University and College Contact Lens Educators (BUCCLE). Marta’s research focuses on generating evidence to support contact lens education and clinical practice. She has presented at numerous national and international conferences and has contributed to the BCLA CLEAR reports.