Question

what are the function of pupils, iris, retina, cornea​

Answer 1

Pupil or Iris, Retina and Cornea all are the part of Human Eye :

Iris or Pupil : Behind the cornea is the Iris. It lends colour to the eye. The amount of pigmentation in the iris gives color to the eye. When the Pigmentation is the highest, the iris is black or brown in colour. When the Pigmentation is least, the eyes is blue in colour. The iris has a central aperture called pupil. The iris regulates the amount of the light entering the eye by adjusting the size of the Pupil in the following ways :

1. If the light is dim, the iris expands the pupil in order to allow more light to enter the eye.
2. If the light is bright, the iris contracts in order to make the pupil decrease the amount of light entering the eye. The iris consist of muscles that expand and contract the pupil.

Retina : It is the innermost delicate membrane having a large number of cells "rods and cones." The cones are sensitive to bright light and can delict color whereas rods are sensitive to dim light.

Cornea : The sclera layer continues in the front of the eye as Cornea. It is the transparent white portion of the eye which covers the transparent bulge on the surface of the eyeball. It allows the light to enter into the eyeball.

MORE TO KNOW :

Human Eye :

• The Human Eye is a light - sensitive organ, which enables us to see the world.
• The eyelids act as the shuttlers of the eyes and protect them from shocks, injuries and bright light.
• When you look at your eye in the mirror, you can see that on the outside, the eye has an eyeball and there is a white plate all around it.
• The eyeball is almost like a spherical ball.
• It has a diameter of about 2.5 cm.

The Outer Part of the eye is composed of three layers of tissues namely :

1. Sclera : Outermost covering of eye.
2. Choroid : Dark pigmented layer.
3. Retina : Delicate Mambrane.