The Structure, Description & Functions Of The Eye

The Eye is light of the whole body and makes vision possible. So if the eye is lost, vision becomes very difficult. Actually there are 5 main sense organs, the sense organ for hearing, the sense organ for taste, the sense organ for smelling, the sense organ for touch and the sense organ for sight which is the eyes. It plays a major role enabling one to interact the beauty things in his environment.

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The eye is found deep in a cavity call orbit or eye socket in the skull and encloses and protects all except the fron of the eyeball. The eyeball is attached to the eye socket by six sets of eye muscles which enables the eye to move in many directions. Below is main parts of the human eye.

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The parts of human eyes

1• Conjunctiva

2• Suspensory

3• Ligament

4• Cornea

5• Iris

6• Aqueous humor

7• Pupil

8• Lens

9•Ciliary body

10• Ciliary muscle

11• Sclerotic

12• Choroid

13• Retina

14• Fovea or Yellow spot

15• Vitreous humor

16• Blind spot

17• Optic nerve

18• Rectus muscle

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Description and function of the parts of Human Eye

The Eyelid and Eyelash:

Eyelid opens and closes under voluntary or reflex action to protect the eye from injury.
Blinking (rapid reflex) serves to distribute tears over the surface of the eye to keep conjunctiva clean and moist. Eyelash traps large air-borne particles.

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Conjunctiva:
Co-ordination of life processes
A thin transparent epithelium covering exposed parts of the eye including the front of the sclera. It is a self-repairing skin kept moist and clean by tears and
the reflex blinking movements.

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Sclerotic layer(Sclera):

A tough, non-elastic fibrous coat on the outside of eyeball. It is opaque and helps to maintain the shape of the eyeball by exerting an opposing force against the outward pressure exerted by the aqueous and vitreous humour.

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Cornea:

A transparent region in the front part of the sclerotic coat. The curved surface of the cornea refracts light passing through and causes light rays to converge at the lens.

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Choroid layer (Choroid):

A layer of tissue lining the inside of the sclerotic coat. It contains black pigment which prevents internal reflection of light in the eye and carries a network of blood vessels which supply oxygen and nutrients to the eye.

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Retina;

A light-sensitive layer of the eye made of specialised nerve cells (photoreceptors): rods (for black and white vision) and the cones (for bright light and colour vision).
It acts as screen on which images are formed.

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Yellow Spot ( Fovea Centralis):

The region of the retina where most cones are located it is the most light sensitive region for sharp colour vision.

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Blind Spot:

A non-photosensitive disc that is devoid of light sensitive cells. It is the region where nerve fibres connecting the rods and cones leave the eye to the optic nerve.

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Optic nerve:

Made up of sensory nerve fibres from rods and cones in the retina. It transmits impulses initiated by different wavelengths of light to the visual region of the brain where the information is processed to form an image.

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Lens:

Made up of soft transparent and elastic material which refracts light entering eye onto the retina. It can become more or less biconvex to focus light from near or far objects on retina.

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Ciliary body (muscle):

A ring of muscle fibres which alter the shape of the lens for focusing.

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Sensory ligament:

They hold lens in place and connect the lens to the Ciliary muscle.

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The eye is very vital organ in human anatomy and therefore we advice that proper care proper care should be taken to keep it very safe so that we don't lose our eye sight. It's advisable to visit the eye Clinic immediately we sense any abnormalities or problem relating to the eye. We must avoid applying eye drops which aren't prescribed by A Doctor. Applying unprescribed medicine may cause a total loss of your eyes.

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