Question

Explain the working of an Human Eye

Answer 1

Answer:

Our vision allows us to be aware of our surroundings. Eighty per cent of everything we learn is through our sight.

Your eye works in a similar way to a camera. When you look at an object, light reflected from the object enters the eyes through the pupil and is focused through the optical components within the eye.

The front of the eye is made of the cornea, iris, pupil and lens, and focuses the image onto the retina. The retina is the light sensitive membrane that covers the back of the eye. This membrane consists of millions of nerve cells which gather together behind the eye to form a large nerve called the optic nerve.

When the light enters the eye, it is focused to a pinpoint on the macula, a small area in the centre of the retina at the back of the eye. The macula is responsible for central detailed vision, allowing you to see fine detail and colour, read and recognise faces.

When light stimulates the nerve cells in the retina, messages are sent along the optic nerve to the brain. The optic nerves from the two eyes join inside the brain. The brain uses information from each optic nerve to combine the vision from the two eyes allowing you to see one image.

Explanation:

Hope it help you

Answer 2

$\textbf{The Human Eye }$:

Human eye is the most important organ. It is used to see the beautiful nature and the natural phenomena. The human eye works on the refraction of light through a natural convex lens made of transparent living material and enable us to see things around us.

$\textbf{The main parts of human eye are }$:

Cornea, Iris, Pupil, Ciliary muscles, eye lens, retina and optic nerves.

1. $\textbf{Cornea}$:

It is transparent part of eye and allow the light to enter in the eyes, it is the outermost part of the eye.

2. $\textbf{Iris}$:

It is a circular diaphragm having a hole in it's centre. This hole is called $\textbf{pupil}$. The circular diapragm has muscles and coloured pigments. The colour of an eye depends on the colour of these pigments. The function of iris is to control the amount of light entering the eye through the pupil. The pupil becomes small when bright light falls on the eye but it becomes wide when there is dim light.

4.$\textbf{Ciliary Muscles }$:

These muscles hold the eye lens in position. It controls the focal length of eye lens. When these muscles contracts the focal length of the lens increases when they expands they exerts pressure on the lens and decreases focal length.

5. $\textbf{Retina}$:

It acts as a screen to obtain the image of object. It contains number of cells in the form of rods and cones which are sensitive towards light. These cells convert light energy to into nerve impulses or signals.

6. $\textbf{ Optic Nerves }$:

Optic nerve is found by the nerve fibres coming from the retina. It transfers nerve impulses to the brain.

$\textbf{Working of the eye }$:

When will look towards an object light from the object enters the pupil of the eye and falls on the eyelens. The lens forms a real and inverted image on the retina of the eye. The retina of the eye contains special cells in the shape of rods and cones. These cells convert light energy into electrical signals. These electrical signals carried to the brain through the optic nerves.