What is the focal length of the corrective contact lens needed by a nearsighted person whose far point is at 60 cm?
A)-60 cm
B)-30 cm
C)+30 cm
D)+60 cm
E)+130 cm

Question

Quizplus · Accepted Answer

The focal length of the corrective lens for a nearsighted person should allow them to see distant objects clearly. Since their far point is 60 cm, the lens needs to correct vision to infinity. The formula for lens power (P) is P = 1/f, where f is the focal length in meters. To make distant objects (at infinity) appear at the person's far point (60 cm), the lens must have a focal length of -60 cm, indicating a diverging lens. This focal length will shift the image from infinity to the person's far point, correcting their nearsightedness.

What Is the Focal Length of the Corrective Contact Lens