Question

A student can see objects clearly only when the objects are lying at distances between 60 cm and 320 cm from the eye. 

(a) What kind of eye defect he is suffering from? 

(b) What kind of lens will be required to increase his range from 25 cm to infinity? Explain briefly.

Answer 1

Student is suffering from myopia. It can be corrected by using concave lens of appropriate focal length and power. The light rays meet before retina and hence concave lens will help the rays to diverge further and help them in meeting on retina.