Question

Draw a labelled diagram of human eye. explain the functions of each part of human eye

Answer 1

★ What is Human eye?

The human eye is an organ which basically reacts with light and allows us to see or vision anything. The eye is a part if sensory nervous system. Basically rod and cone cells in retina allow conscious light perception and vision including the colour differentiation and the perception of depth.

★ What are the function of eyes?

Basically eyes receives the oxygen through the aqueous. Its main function is to nourish the iris, and lens by carrying the nutrients. and it removes waste product which excreted from the lens.

★ Some part of human eye :-

● Cornea :- The cornea is the clear bulging surface in front of the eye. It is the clear window at the front of the eye which covers the eyes and the pupil. The front part of the sclerotic is transparent to light and termed as cornea.

● Iris :- The iris is just at the back of cornea that control the size of pupil. It is also known as the photographic camera and allows the regulated amount of light enters in our eyes.

● Retina :- The retina serves the purpose of screen of the eye. Where the image of the eye basically formed.

● Optic nerve :- It carries the information to brain.

● Pupil :- At the centre of the human iris their is a hole through which light falls on the lens thats called pupil.

● Eye Lens :- Eye lens is a double convex lens with the help of which image is formed at retina by the refraction of light.

★ Extra Point :- The human eye is a ball about 2.5 cm in diameter.

________________________________

Answer 2

$\huge\bigstar{\underline{\text{\green{Human\:Eye}}}}$

$\large\bigstar{\underline{\sf{\blue{Human\:Eye:-}}}}$

Two eyes are located in sockets of the skull called orbits. The adult human eyeball is nearly a spherical structure. The wall of the eyeball is composed of three layers. They are:

• Sclera
• Choroid
• Retina

$\large\bigstar{\underline{\sf{\blue{Sclera:-}}}}$

It is the external layer formed of a dense connective tissue. Anterior transparent portion of sclera is called cornea.

$\large\bigstar{\underline{\sf{\blue{Choroid:-}}}}$

Bluish middle layer contains many blood cells. Choroid is thin over posterior two-thirds of the eyeball, but it is thick in anterior part to form ciliary body.

Ciliary body continuous forward to form a pigmented and opaque structure called the iris. It is the visible coloured portion of the eye.

Iris as central opening called pupil. The diameter of the pupil is regulated by muscle fibres of iris.

The eyeball contains a transparent crystalline lens. It is held in place by ligaments attached to the ciliary body.

$\large\bigstar{\underline{\sf{\blue{Retina:-}}}}$

Inner layer contains three layers of cells from inner to outer. They are:

• Ganglion cells
• Bipolar cells
• Photoreceptor cells

Here, Photoreceptor cells are of two types, they are rods and cones. They contain light-sensitive proteins called photopigments.

_______________________________________________________________