Quiz 18: WS11.3 answers

Kowloon Tong School (Secondary Section)

F.2 Integrated Science Quiz 18 WS11.3,4

Words Translation (7 marks)

	Chinese term	English term
1	限制	Limitation
2	近視	Short sight
3	遠視	Long sight
4	白內障	Cataract
5	色盲	Colour-blindness
6	凹透鏡	Concave lens
7	凸透鏡	Convex lens

Fill in the Blanks (23 marks)

1        Our eyes have limitations. We cannot see objects (1)clearly when they are too close or too far

away. We cannot see objects that are too (2)small such as micro-organisms in the sea.

2        We can use suitable (3)instrument to overcome some of the limitations of our eyes, e.g. hand lens and microscope.

3        Besides limitations of our eyes, if we have eye (4)defects, we cannot see things clearly.

4        If a person has (5)short sight, he can see near objects but not (6)distant objects clearly.

It is because the lens is (7)thicker than normal or the eyeball is too (8)long.

The light from a distant object is focused (9)in front of the retina.

It can be corrected by wearing spectacles with (10)concave lens.

5        If a person has (11)long sight, he can see distant objects but not (12)near objects clearly.

It is because the lens is (13)thinner than normal or the eyeball is too (14)short.

The light from a near object is focused (15)behind the retina.

It can be corrected by wearing spectacles with (16)convex lens.

6        The lens of an eye is normally (17)clear / colourless. If the lens becomes cloudy, vision

becomes unclear. This eye defect is called a (18)cataract. This can be treated by replacing the

cloudy lens with an (19)artificial lens.

7        Some people cannot distinguish certain (20)colours because they have (21)colour-blindness.

Many of them cannot distinguish between (22)red and green.

       This is a (23)inhereditary disease and cannot be cured.

Challenging Questions (Bonus 3 marks)

1.      Draw and label a suitable lens to correct the eye defect of a person who cannot see near object but can see distant object clearly. Also, draw the path of the light from a near object entering his eye.