Question

A myopic (nearsighted) person has a far point distance of 110 cm. What is the refractive power of his ideally prescribed eyeglasses if he wears his eyeglasses a distance of 3.0 cm from his eyes?

Answer 1

The power of his ideally prescribed eyeglasses is 1.0 D.

Step-by-step explanation:

Given that,

Image distance = 110 cm

We know that,

Object distance = ∞

We need to calculate the focal length

Using formula of lens

`(1)/(f)=(1)/(u)+(1)/(v)`

Put the value into the formula

`(1)/(f)=(1)/(-110)+(1)/(\infty)`

`f=-110\ cm`

We need to calculate the power of his ideally prescribed eyeglasses

Using formula of power

`P=(100)/(f)`

`P=(100)/(110)`

`P=0.90 = -1.0\ D`

Hence, The power of his ideally prescribed eyeglasses is 1.0 D.