The near point of a farsighted person is 65 cm. What power contact lens must he use to correct this problem and be able to read a book at a normal near point of 25 cm?
A) -2.4 diopters
B) +4.2 diopters
C) -4.2 diopters
D) +2.5 diopters
E) -2.5 diopters

Question

Quizplus · Accepted Answer

To correct farsightedness, the lens must bring the near point from 65 cm to 25 cm. Using the lens formula (1/f = 1/v - 1/u) and converting to diopters (P = 1/f), we find the power needed is +2.5 diopters.

The near Point of a Farsighted Person Is 65 Cm