(a) Explain the functions of the following parts of the eye: (a) cornea (b) iris (c) pupil (d) ciliary muscles (e) eye-lens (f) retina (g) optic nerve (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.

(a)The cornea is the portion of the eye’s front that allows light to enter.
(b) Iris: The iris regulates how much light enters the eye.
(c) Pupil: The pupil controls how much light enters the eye.
(d) Ciliary muscles: These help the eye lens to contract and relax.
(e) The eye lens aids in concentrating light on the retina.
(f) The retina, which has cells known as rods and cones, reacts to the brightness of the light and the colour of objects.

(g) Optic nerve: The optic nerve transmits the image created on the retina to the brain.

(b) The pupil compresses as we move from a dark environment into light, and the pupil widens as we move from light into a dark environment.
(c) Because the pupil has contr

acted when we are in bright sunshine, we cannot see the seat clearly when we enter the theatre. However, the pupil widens when we enter the hall, allowing for the passage of more light.