The eye works like a camera. When you focus on an object, light that was reflected from the object
enters the eyes by the pupil and is focused through the parts inside the eye. When light stimulates the
nerve cells in the retina, messages are sent by the optic nerve to the brain. The optic nerve is a bundle of
more than 1 million nerve fibers.
It is the second cranial nerve or cranial nerve II. It passes on sensory
details for vision in the form of electrical impulses from the eye to the brain. The optic nerves from the
two eyes combine in the brain. The brain then utilizes the information from each optic nerve to join the
vision from the two eyes letting you see one image. First of all, light passes through the cornea which is
the clear front surface of the eye. The cornea bends light to aid the eye to focus. Some of the light goes
into the eye by the pupil, while the iris controls how much light the pupil lets in.
Light passes through the lens which works together with the cornea to focus light accurately on the
retina. When light hits the retina, special cells called photoreceptors convert the light into electrical
signals and these electrical signals move from the retina through the optic nerve and then to the brain.
Finally, the brain turns the signals into the figures you see. Our eyes also need tears to work correctly.
The tears work hard not only to protect the eyes, but also to wash out irritants, soothe our emotions, and
even communicate to those around us. There are so many causes why we cry, tears are a sign of health
and in various methods in terms of emotional tears is just being a human.