Human Eye Parts and its Functions - INDIA COVER

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Human Eye Parts and its Functions

Human Eye Parts and Functions

Human Eye Parts and Functions

Human Eye is used for to see all visible things through eye parts, and unable to see clearly if they are affected by any other defects. Now we are going to discuss in detail about the Human Eye Parts, Function,Defects

Human Eye Parts

The Important parts of Human Eyes are :-
  • Sclera
  • Choroid
  • Cornea
  • Iris
  • Pupil
  • Lens
  • Muscles
  • Fluid

Human Eye Functions

  • It is the tough Outer Coat that Protects the eye ball.
  • It is the Vascular layer of the eye contains blood vessels that nourishes the inner part of the eye.

  • Front portion of the eye
  • Convex Shape and bulges outside
  • Light enters the eye through Cornea.


  • Dark Muscular diaphragm, located behind Cornea.
  • Regulates amount of light enters the eye by adjusting the size of the pupil.

  • It is the hole in the middle of the Iris
  • Size of the Pupil decreases or Increases depending upon the intensity of light entering the eye.

Why the Size of the Pupil Decreases ?

  • High Intensity of light ( sun) entering the Eye the Pupil Size decreases

  • It is transparent jelly like substance made up of proteins.
  • It is held by Cilary Muscles and Suspensory Ligaments
  • The important function of the muscles, such as cilary muscles and suspensory ligaments ,which adjust the focal length of the eye. so we can able to see distant and nearby objects clearly.
  • If the cilary muscles is contracted ,the suspensory muscles gets relaxed and Lens become thick and focused for the close vision.
  • If the Cilary Muscles is relaxed, the suspensory muscles gets contracted and now the Lens become thin and focused for the distant vision.
  • Changing the focal length of focus is called as Accomodation.

  • Based on the fluid types there are two fluids :- one is vitreous humar liquid, and another is Aqueous humour liquid.
  • Aqueous humour liquid is the viscous liquid filled in the area between Cornea and Eye Lens.And it Prevents Eye from Collapsing.
  • Vitreous Humour is the liquid tha presents behind the Lens in the Retina. And it helps in maintaining the shape of eye.


  • Inverted Real Image is formed in the retina
  • It gets activated and generate electrical signals.
  • Electric signals are generated by the cells are sent to the brain through optic Nerve.
  • In this part it consists Macula, Light sensitive cells, optic nerve.
  • Macula - It is the depressed layer in the retina its main function is clear and sharp vision.
  • In this depressed layer it contains maximum number of  cones are present.
  • It has large number of Light sensitive cells
Light Sensitive Cells

  • Light Sensitive Cells are of two types which are :-
  • Rods - cells respond intensity of light.
  • Cones- cells respond colour of light.
Blind Spot

  • The blind spot is located infront of the optic nerve connects to the retina.

Defects in Eye
Hypermetropia or Long Sighted person

  • A person can see the objects only which is at the Longer distance
  • It is due to the contraction of the eye ball and focal length.
Which Lens is used to correct the Hypermetropia ?
Convex Lens of the focal length is used to correct these defects.

Myopia :
  • A person can able to see only nearby objects
Which Lens is usesd to correct the Myopia ?
Concave Lens is used to correct these defects and it is minus powered Lens.

End of the session :-

In this article we have discussed about the importance parts and functions of human eye.
And we saw lot of different parts ,defects in the eyes, and all the corrective measures for the defects.

Thanks for reading the article .Keep Supporting us.

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