The working of eye is illustrated pointwise as follows -

1. Light rays enter the eye through the cornea of the eye. The refractive power of cornea bends the light rays in such a way that they pass freely through the pupil in the center of the iris.

2. The iris works like a shutter in a camera. It can enlarge and shrink, depending on how much light needs to enter the eye.

3. After passing through the iris, the light rays pass through the crystalline eye lens. It helps to focus light rays properly.

4. Then the light rays pass through a dense, transparent substance called as the vitreous humor which helps the eye hold its spherical shape. This layer helps to focus the light rays on the retina as it is a dense layer.

5. The retina is responsible for capturing all of the light rays, processing them into light impulses through millions of tiny nerve endings. It then sends these light impulses through over a million nerve fibers to the optic nerve which are inetrpreted as image by the brain.