Question

9. What are the functions of the following parts of the eye?
(a) Iris
(b) Eye-lens
(c) Ciliary muscles
(d) Retina
(e) Optic nerve

Answer 1

Answer:

a) Iris: It controls the amount of light entering the eye.

b) Eye-lens: It focuses light on to the retina. d) Retina: It is a delicate membrane having a large number of light-sensitive cells called 'rods' and 'cones' which respond to the intensity of light and colour of objects respectively.

e) Optic nerve: It conveys the image formed on the retina to the brain.Pupil: It controls the illumination in the eye.

c) Ciliary muscles: The focal length of the eye-lens can be changed by changing its shape by the action of ciliary muscles.

Answer 2

Explanation:

A)

a. Cornea: It is the fromt part of the eye. The light coming from objects enters the eye through cornea.

b. Iris: It controls the amount of light entering the eye.

c. Pupil: It controls the illumination in the eye.

d. Ciliary muscles: The focal length of the eye-lens can be changed by changing its shape by the action of ciliary muscles.

e. Eye-lens: It focuses light on to the retina.

f. Retina: It is a delicate membrane having a large number of light-sensitive cells called 'rods' and 'cones' which respond to the intensity of light and colour of objects respectively.

g. Optic nerve: It conveys the image formed on the retina to the brain.