With nearly 30 years of experience in teaching optics, Dr. Keating offers a new edition of this reader-friendly book to enhance your understanding of geometric, physical and visual optics. Written primarily for optometry students, the core of basic optics, including thin lenses, ametropia corrections, accommodation, introductory astigmatism and refraction techniques, prisms, and prisms in lenses, are contained in the first 12 chapters. Many students need percolation time to absorb some of the abstract concepts in optics. Dr. Keating introduces some concepts in early chapters and then returns to a more advanced treatment in later chapters providing you with adequate time to absorb difficult concepts. Completely revised and updated, the reader should benefit from new and rewritten sections on: axial magnification, Jackson Cross Cylinder tests, retinoscopy, reflex motions, field of view, the optics of indirect ophthalmoscopy, optical aberrations, diffractive lenses, the Doppler shift, lasers and the similarities and differences of Gaussian laser beams versus the propagation of light from a point source, plus, a new appendix on angles and basic trigonometry. Although not a matrix optics text, matrices are used extensively in the chapters on spherical systems and off-axis aspects of astigmatism. In particular, the matrix treatment of astigmatism serves as a foundation for the recently developed, much improved statistical techniques that deal with refractive corrections and astigmatism in all its aspects.