Question

A person is able to see objects clearly only when these are lying at distance between 50 cm and 300 cm from his eyes.

Answer 1

Answer:

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

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

ANSWERS;                                                        (a) The person is suffering from both myopia and hypermetropia.

(b) He has to use bi-focal lens to increase his range of vision from 25 cm to infinity. The upper portion (concave lens) facilitates distant vision and the lower portion (convex lens) facilitates near vision.

Explanation: