Describir: Refraction of the human eye and methods of estimating the refraction including a section on the the fitting of spectacles and eye-galsses, etc. / by James Thorington, A. M., M. D. emeritus professor of diseases of the eye in the Philadelphia Polyclinic and College for graduates in medicine; member of the American Ophthalmological Society; fellow of The College of Physicians of Philadelphia, etc. Three hundred and forty-four illustrations twenty-seven of which are colored