Explain the functions of various parts of a human eye.

Asked by Rupal Sinha | 6th Dec, 2013, 08:47: PM

Expert Answer:

Structure of human eye

The human eye is roughly spherical in shape with diameter of about 2.3 cm. It consists of a convex lens made up of living tissues. Hence, human lenses are living organs contrary to the simple optical lenses.

The white of the eye is known as the sclera . It is the tough, opaque tissue that protects the outer layer of the eye. Iris is the coloured part of the eye, and the pupil is the black,

The main parts of the human eye and their respective functions are:

 

Sr. No.

Human eye part

Function

1.

Pupil

Opens and closes in order to regulate and control the amount of light

2.

Iris

Controls light level similar to the aperture of a camera

3.

Sclera

Protective outer coat

4.

Cornea

Thin membrane which provides 67% of the eye’s focusing power

5.

Crystalline lens

Helps to focus light into the retina

6.

Conjunctiva

Covers the outer surface (visible part) of the eye

7.

Aqueous humour

Provides power to the cornea

8.

Vitreous humour

Provides the eye its form and shape

9.

Retina

Captures the light rays focussed by the lens and sends impulses to the brain via optic nerve

10.

Optic nerve

Transmits electrical signals to the brain

11.

Ciliary muscles

Contracts and extends in order to change the lens shape for focusing.

 12.         Eye Lids           Eye lids are provided to control the amount of light falling on the 
                                   eye. They also protect the eye from dust particles etc.

Answered by Faiza Lambe | 7th Dec, 2013, 10:09: AM

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