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As it rightly says on the back cover, Clinical Optics and Refraction by Andrew Keirl and Caroline Christie offers a 'how to' approach. The style of simple phraseology and examples in the text are a means of clearly putting across a subject which many think of as dry and boring. This book tries to dispel this myth and does, on balance, succeed.
Each chapter has 'concluding points' which are a good summary of what you have read. However, at times I did find some comments which described the length and complexity or importance of the chapter unnecessary. Surely the subject is in the book because it needs to be known, however lengthy or otherwise the chapter.
Recommended reading
These points were followed by a 'recommended reading list' which, rather than references, seemed appropriate. Sometimes the layout could have been better designed for text and equations but that is a publishing issue not an author problem. It was also a shame that all the pictures were in greyscale. There are colour plates of certain figures at the back, but it is a shame these could not be incorporated in the actual text. However, the main thrust of the book is to make all the refraction facts and formulae come to life by easy step-by-step methods of working through equations and ray traces and this it achieves.
The book is in two parts, the first being all the subjects associated with optics of the eye, ametropia and its correction, while the second is devoted to contact lenses and their application in vision correction. The clinical refraction elements are split into 16 chapters each with a clear progression of the topic and good explanatory line drawings. A summary of equations and expressions is a useful guide to a better understanding, especially in subjects like the correction of spherical ametropia. The way examples are used in subjects such as 'The Basic Retinal Image Size' makes this a very useful book for those at any level who wish to learn or refresh their basic knowledge. Andrew Franklin helps with four chapters on the different aspects of subjective and objective refraction, while William Harvey covers automated methods.
Contact lenses
Whether a chapter in part 2 on contact lens materials is relevant to the subject matter of the book is debatable, but it is nicely written.
The soft and RGP toric chapters try to make sense of what we do these days with a computer programme. This basic knowledge as to how these programmes may be devised must be learnt even if not used later in one's professional life.
The presbyopia chapter starts with the fitting of suitable methods of contact lens correction, which is possibly not as necessary as the calculations involving multifocal lenses which are what this book is all about. The thought behind this approach was probably to give complete coverage of the subject, while putting the calculations into perspective. The good basic contact lens chapters on over refraction techniques, accommodation and convergence, axial and radial edge thickness and verification guide one through the maze of equations with clarity.
The final chapters by Bruce Evans emphasise that a basic binocular vision assessment should always be included as part of a contact lens aftercare as well as an eye examination.
It is notable that only the chapters by Andrew Kierl have the optical equations we need to help understand the outcomes. It is targeted at both undergraduates and newly qualified optometrists, contact lens opticians and dispensing opticians and I believe it is set at the correct level. But it should also be marketed to those who are going for higher qualifications. Without this basic visual optics knowledge one would not be able to easily pass a higher diploma.
? Judith Morris is associate director of contact lens teaching at City University