Camera - a light-tight box with a lens system for forming a real image on a light sensitive film.

The eye is basically a light tight box, its outer walls are formed by the hard white sclera.

Scarlea - (Greek) hard.

Focusing of light is done by a two-piece lens system. The outer lens piece is called the cornea, and the inner piece is a crystalline lens (eyelens). The lens system forms an inverted image on the retina at the back of the eye. 

Rete - (Latin) net - the nerve cells give the retina the appearance of a net.

Light enters the inside of the eye through the pupil, which corresponds to the aperture of a camera.

Pupa - (Latin) doll. You can see a small image of yourself in another’s eye. 

The main chamber of the eye is not empty, but filled with jelly-like liquid, the vitreous humor. The space between the cornea and the eyelens is filled with aqueous humor.

Vitreus - (Latin) glassy.
Aqueus - (Latin) water.
Humor - (Latin) fluid.

The internal pressure of those fluids helps to hold the shape of the eyeball.

The retina of the eye is covered with over a hundred million light-sensitive cells (rods and cones) which are packed together very tightly, similar to the chambers of a honeycomb. At approximately the center of the retina there is a region called the fovea: there are a large number of cones there and no rods. This region is responsible for very precise color vision. The rods and cones are connected through a system of nerve cells in the retina to the optical nerve. There are only about one million nerve fibers in the optic nerve, therefore each fiber is connected to many rods and cones. At the point where the optic nerve leaves the eye there are no rods and cones, so you can’t see light there. This region is called the blind spot. Even though you can’t see there your brain fills in that spot for you.

For the human brain to build a detailed picture of the surrounding scene the eye must scan the surroundings.