...to the same focus. Now this very adjustment is made in the eye, by the arrangement of the curvatures of the cornea and of the two surfaces of the crystalline lens ; and in the well-formed eye it is so perfect as to produce complete distinctness in the image or picture...

...to the same focus. Now this very adjustment is made in the eye, by the arrangement of the curvatures of the cornea and of the two surfaces of the crystalline lens ; and in the well-formed eye it is so perfect as to produce complete distinctness in the image or picture...

...phenomenon could have been given. M. Cramer has succeeded in determining on the living eye the curved ray of the cornea, and of the two surfaces of the crystalline lens. In so doing he followed Samson's method, and observed the images thrown by a luminous object, whose...

...astigmatism. The rapid advance which practical ophthalmometry is making may soon give us an instrument to measure the curvature of the posterior surface of the cornea and the curvature and obliquity of the lens, for information regarding which we must now rely on other...

...astigmatism. The rapid advance which practical ophthalmometry is making may soon give us an instrument to measure the curvature of the posterior surface of the cornea and the curvature and obliquity of the lens, for information regarding which we must now rely on other...

...physiologique" (Paris, 1898). There is, besides, a fairly full literature on the form and the functions of the posterior surface of the cornea and of the two surfaces of the lens ; on the influence of paracentral zones of the cornea during vision with a greater or less degree...

...(j^ metre) in front of a screen representing the retina. The measurements of the radii of curvature of the cornea and of the two surfaces of the crystalline lens are, however, found to vary notably in different eyes, and this without giving rise to any corresponding...