Question

(a) Explain the functions of the following parts of the eye
(i) cornea
(ii) iris
(iii) pupil
(iv) ciliary muscles
(v) eye-lens
(b) If you walk from a dark room into sunlight and back again into dark room, how would your pupils alter in size? What makes this happen?
(c) Explain why, we cannot see our seats first when we enter a darkened cinema hall from bright light but gradually they become visible.

Answer 1

Answer:

ek tuhi yaar mera tera kya dunya se milna

Answer 2

Explanation:

• (a)  (i) Functions of cornea: Eye’s front part that is convex in shape and made up of transparent substance is called cornea. It helps in sending the light to the eye.
• (ii) Functions of iris: Iris helps in regulating and controling the amount of light that automatically enters the eyes. This is done by adjusting the pupil’s size as per the light’s intensity received by the eye.
• (iii) Functions of pupil: The amount of light entering the eye is regulated when the pupil contracts and expands.
• (iv) Functions of ciliary muscles: The lens of the eyes are relaxex or contracted by the ciliary muscles. This helps in altering its focal length to focus the pictures of distant or nearby objects.
• (v) Functions of lens: The function of the lens is to the converge an object’s light rays.
• (b) When you are in a dark room, you need large amount of light for your eye. So, the size of your pupil will be large to get in more light inside. Then, when you go outside into sunlight, the size of the pupil decreaes as the eye can’t take in more light. The process continues when you keep moving in and out.
• (c) We cannot see the seats clearly when we enter the cinema hall as the size of the pupil is small when we are outside. As the pupil enlarges to get in more light, we will be able to find our seats.