Question

The focal length of the glasses of a short sighted person is 37.5 cm. Calculate the power of the glasses and their nature.

Answer 1

As the person is short sighted the lens of his glasses is concave.

Applying, \[ \mathrm{P} = \frac{100}{f \text{(in cm)}}\]

\[= \frac{100}{-37.5}\]

= −2.67 D

Minus sign indicates that the lens is concave in nature.