What are facts about eyes and ears?

Eyes

* The human eye can see more colors than a camera.

* The cornea is the clear outer layer of the eye that covers the iris and pupil.

* The iris is the colored part of the eye.

* The pupil is the black hole in the center of the iris that light enters the eye.

* The lens is a transparent structure behind the iris that helps to focus light on the retina.

* The retina is the light-sensitive tissue at the back of the eye that converts light into electrical signals that are sent to the brain.

* The macula is a small area in the center of the retina that is responsible for sharp central vision.

* The optic nerve is a bundle of nerve fibers that carries visual information from the retina to the brain.

Ears

* The human ear can hear sounds as low as 20 hertz and as high as 20,000 hertz.

* The outer ear is the visible part of the ear that collects sound waves and directs them into the ear canal.

* The ear canal is a tube that leads from the outer ear to the middle ear.

* The middle ear is a small cavity that contains the eardrum and three small bones called the malleus, incus, and stapes.

* The eardrum is a thin membrane that vibrates when sound waves hit it.

* The malleus, incus, and stapes are three small bones that amplify the vibrations of the eardrum and transmit them to the inner ear.

* The inner ear is a fluid-filled labyrinth that contains the cochlea, semicircular canals, and vestibular system.

* The cochlea is a spiral-shaped tube that contains the auditory receptors.

* The semicircular canals are three fluid-filled tubes that help with balance.

* The vestibular system is a series of fluid-filled sacs and tubes that help with balance.