Question

someone you know is nearsighted. the far point of their eyes is 48 cm. what is the focal length of the eyeglasses lens that would allow them to see an object really, really far away? assume the lens sits 1.5 cm away from their eyes.

Answer 1

The power of the eyeglass lens needed to correct the vision of a nearsighted person with a far point of 48 cm is 0.02 D.

Step-by-step explanation:

To calculate the power of the spectacle lens needed to correct the vision of a nearsighted person, we can use the formula:

Power of lens = 1 / focal length

The far point of the person's eyes is given as 48 cm. To find the focal length of the lens, we subtract the far point from infinity:

Focal length = 1 / (infinity - far point)

= 1 / (1 / ∞ - 1 / 48)

= 48 cm

The power of the lens is the reciprocal of the focal length:

Power of lens = 1 / 48

= 0.02 D