Question

Study the diagram given below and answer the questions that follow:

1. Name the defect of vision represented in the diagram. Give reason for your answer.
2. List two causes of this defect.
3. With the help of a diagram show how this defect of vision is corrected.

Answer 1

1. The diagram represents hypermetropia, commonly known as farsightedness. This refractive defect allows for clearer vision of distant objects than nearby ones. This issue arises when the eyeball is too short, or the cornea has insufficient curvature, leading light to focus behind the retina instead of directly on it. 
   Individuals with hypermetropia can easily see distant things but struggle with close-range vision. A hypermetropic person's near point is farther away from the eye than the standard 25 cm distance. To read comfortably, hold items at a distance of at least 25 cm. 
2. Two causes of the defects are:
   1. The focal length of the eye lens is too long.
   2. The eyeball has become too small.
3. The defect of vision is corrected by using a convex lens, as shown below.