Question

A. Differentiate the eye defects: Myopia and Hypermetropia
B. Explain the process of correction of eye defects using suitable diagram.
C. Why are traffic signals red in colour? [7 Marks]

Answer 1

A. Difference between myopia and hypermetropia [2 Marks]
B.

• Myopia is commonly known as near-sightedness.
• In this condition, the person can see the objects nearby but cannot see distant objects clearly.
• Faraway objects appear blurry, and a person will not be comfortable seeing them.
• Myopia condition takes place when the shape of the eyes leads the light rays to bend in a wrong way, focusing images in front of the retina rather than focusing on the retina.
• Myopia is explained in the figure below.

• Hypermetropia is commonly known as far-sightedness.
• In this condition, the person can see objects at a distance but cannot see nearby objects clearly.
• Usually, the person with this disorder squints to see nearby objects.
• Hypermetropia is caused when the light rays from a closeby object are focussed at a point behind the retina.
• The condition of hypermetropia is clearly explained in the figure below.

[4 Marks]

C.
We know among the seven colours of white light, red colour has maximum wavelength. That is why red colour is least scattered by atmospheric dust and other particles. Hence red colour is used to indicated any danger sign. [1 Marks]