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It there- fore projects outwards in front of the eye, rendering that axis of the eye which passes through its centre a little longer than the diameter, which is at right angles to it. The cornea being of nearly uniform thickness, the concavity of its inner surface corresponds with the convexity of its outer, and gives the whole the character and form of a watch-glass, or a concavo-convex lens, whose surfaces have equal radii. 311 Optic axis. In looking at an open eye, that part of the sclerotica which is uncovered is what is popularly called the white of the eye, and the cornea covers the coloured part. A. prev next |