Question

A person with myopic eye cannot see object beyond 2m directly.what should be the type of the lens used?what should be its power?

Answer 1

Hey Friend,

Since the person suffers from Myopia, the corrective lens will be concave or diverging lens.

Given, that the person can't see objects beyond 2 m directly. 
So, in order to view the distances beyond 2 m, the focal length of the lens should be 2 m.

Power of lens = 1 /  focal length (in meter)
P = 1/(-2) 
P = -0.5 Diopter

Therefore the power of the lens should be - 0.5 D

Hope it helps!