Question

The far point of an eye is 180 cm. A corrective lens is to be used to allow this eye to focus clearly on objects a great distance away. What should be the focal length of this lens

Answer 1

Answer:

The focal length of this lens is f = 0.55 D

Explanation:

Given that the far point of an eye ( d )=  180 cm = 1.8 m

We know that focal length of lens is given by

$f = \frac{1}{d}$

Put the value of d in above equation we get

$f = \frac{1}{1.8} \ m^{-1}$

f = 0.55 D

Therefore the focal length of this lens is f = 0.55 D