The author states that Optics serves the student ophthalmologist "as preparation for his study of refraction of the eye and as background for his understanding of physiological optics and visual physiology." The broad field of elementary geometrical optics is treated thoroughly, with particular emphasis on the ophthalmic aspects of this subject. An attempt has been made to restrict the use of mathematics, and the mathematics present does not require unusual aptitude.
Orientation is provided by a brief introductory review of the physical nature of light. A clear explanation of the vergence concept results in an intuitive understanding of image-formation by thin lenses. Thin-lens theory is applied to the problems of ocular refraction, and the characteristics of the optical system of the eye are described. Equations and diagrams assist in presenting the theory of image-formation by optical systems and by spherical refracting surfaces. The aberrations of spherical surfaces and the astigmatism