Question

If the distance of the far point for a myopia pa dent is doubled, the focal length of the lens required to cure it will become:

• A. double
• B. half
• C. the same but a concave lens
• D. the same but a convex lens

Answer 1

Answer: (A)

double

Answer 2

In the eye defect of myopia, the focal length of lens $f=-d,$ here d is the distance of far point. Therefore, if $d$ is doubled the focal length will also be doubled.