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)-4.2 diopters
B)-2.5 diopters
C)-2.4 diopters
D)+4.2 diopters
E)+2.5 diopters

Question

Quizplus · Accepted Answer

The power of the lens needed is calculated using the lens formula: 1/f = 1/v - 1/u. Here, v = 25 cm (normal near point) and u = -65 cm (current near point). Solving gives the power as +2.5 diopters.

The near Point of a Farsighted Person Is 65 Cm