Question

A man with defective eyes cannot see distinctly object at the distance more than $60cm$ from his eyes. The power of the lens to be used will be:-

• A. $+60D$
• B. $-60D$
• C. $-1.66D$
• D. $\frac{1}{1.66}D$

Answer 1

The correct option is C $-1.66D$

As we know,

$f=-d=-60cm$
$\therefore P=\frac{100}{f}=-\frac{100}{60}=-\frac{10}{6}=-1.66D$