Question

4. A person is able to see objects clearly only when these are lying at distances
Between 50 cm and 300 cm from his eye.
(a) What kind of defects of vision is he suffering from?
(b) What kind of lenses will be required to increase his range of vision from 25 cm to
infinity? Explain briefly.​

Answer 1

1) He is not able to see both near and far object...so this shows that he is suffering from both hypermetropia and myopia

1) He is not able to see both near and far object...so this shows that he is suffering from both hypermetropia and myopia2)He required both concave and convex lense, together,which is called bifocal lense...In spectacles,both lenses are attached ,one lens at the bottom and other upward

{hope it helps}