Question

A man can see the objects up to a distance of one metre from his eyes. For correcting his eyesight so that he can see an object at infinity, he requires a lens whose power is

• A. +0.5 D
• B. +1.0 D
• C. +2.0 D
• D. –1.0 D

Answer 1

The correct option is D –1.0 D

Hey, like you just learned, for correcting the myopic eye, the concave corrective lens should form the image for an object at infinity at the far point of the defective eye.
Applying sign convention, f = –(far point of myopic eye) = – 100 cm. So power of the lens $P=\frac{100}{f}=\frac{100}{-100}=-1D$