Question

A person cannot read newspaper placed nearer than 50 cm from his eyes. Name the defect of vision he is suffering from. Draw a ray diagram to illustrate this defect. List its two possible causes. Draw a ray diagram to show how this defect may be corrected using a lens of appropriate focal length.

Answer 1

The person is suffering from Hypermetropia i.e. far-sightedness.

Hypermetropia is caused due to:

(i) The focal length of the eye lens is too long

(ii) Decrease in the length of the eyeball

This defect can be corrected using convex lens of appropriate focal length.