Structure of the eye

T he Eyelids are mostly composed of skin, muscles for movement and glands for secretion of oil into the tears to keep the tears from evaporating too quickly. The eyelids protect the eye from strong light, dust and foreign objects. Closure of the lids during sleep protects the surface of the eye from drying. Blinking the eyelids lubricate the eye.

The Palpebral Fissure is the space between the upper and lower eyelids.

The Eyebrows help to protect the eyes from dust and direct sun light. In addition, they prevent sweat from dripping in the eyes.

The Eyelashes are short hairs arising from the eyelids margin and help protect the eye from sun light and dust. The eyelashes are more numerous in the upper lid than the lower.

The Conjunctiva is a transparent thin membrane that covers the front of the eyeball and lines the inside of the eyelids. The conjunctiva is loose enough to allow the eye to move freely. It contains cells that liberate mucus into the tears, helping the tears to spreads evenly over the front surface of the eye.

The Tears are produced by the lacrimal glands. The tears flow down the front of the eye and drain through small pores on the eyelids margin. Then tears flow down the lacrimal tubing and finally drain into the nose. The tears wash the eyes and carry foreign objects to the side of the eye.

The Cornea is the clear crystal part of the front surface of the eye. In addition to protecting the delicate structures inside the eye, the cornea helps focus rays of light on the retina to create an image. Its working is similar to that of the lens of a camera, focusing rays of light to create an image on the film.

The Sclera, the white of the eye, is the outer fibrous protective coat of the eye. It helps maintain the shape of the eye and receives attachments from the muscles, which move the eye.

The Iris is colored part of the eye which lies behind the cornea and inside the eye. It is composed of muscles and contains pigments. The iris has a hole in its center called the pupil. The iris can change the size of the pupil, by its muscles, to control the amount of light entering the eye.

The Lens is the flexible, transparent structure found behind the iris. It is held in place by ligaments called zonules. In order to see clearly objects at different distances, the lens has the ability to change its shape to focus images on the retina. This process is known as accommodation.

The Optic Nerve is a bundle of nerve fibers, which transmits the visual information from the retina to the brain.

The Orbit is a pear shaped cavity in the skull; representing the bony housing of the eye. It provides the protection for the eye, mainly from trauma.

The Eye Muscles: there are six muscles around each eyeball, working together to move the eye in all directions. These muscles are called the extra-ocular muscles and are attached to the bones of the orbit and to the surface of the sclera.

	to be composed of	складатися з
	glands of secretion	залози секреції
	to evaporate	випаровувати(ся)
	tear	сльоза
	to lubricate	зволожувати, змащувати
	palpebral fissure	очна щілина
	eyelid	повіка
	conjunctiva	кон’юнктива
	sclera	склера
	margin	край, грань
	to liberate	звільняти
	lacrimal gland	слізна залоза
	cornea	рогівка
	iris	райдужна оболонка
	retina	сітківка
	flexible	гнучкий
	lens	кришталик
	ability	здатність, вміння
	pear- shaped	грушеподібний
	to blink	кліпати, моргати