The convergence of light rays in the eyeball begins in the aqueous humor is perfected in the crystalline. But when they strike the vitreous humor, which is concave on its front surface, and also less dense than the crystalline, they diverse or spread out, and are thrown upon the back part of the eye.

Convergence of Rays in the Aqueous Humor of the Eyeball

The convergence of light rays in the eyeball begins in the aqueous humor is perfected in the crystalline.…

Plan of the eye seen in section. Labels: A, The Sclerotic Coat; B, The Choroid Coat; C, The Retina; D, The Optic Nerve; E, The Cornea; F, The Aqueous Humor; G, The Iris; H, The Ciliary Processes; I. The Crystalline Lens; K, The Vitreous Humor.

Diagram of the Eye

Plan of the eye seen in section. Labels: A, The Sclerotic Coat; B, The Choroid Coat; C, The Retina;…

Section of the eye magnified, showing the crystalline lens in its proper situation, between the aqueous and vitreous humors.

Section of the Eye

Section of the eye magnified, showing the crystalline lens in its proper situation, between the aqueous…

In passing through the crystalline, the rays cross each other, so that those rays which pass from the lower part of an object are presented uppermost in the bottom of the eye and the reverse, so that the images of object are always inverted, or bottom side upwards. Labels: a, the aqueous; c, the crystalline; v, the vitreous humor.

Formation of an Image on the Eyeball

In passing through the crystalline, the rays cross each other, so that those rays which pass from the…