What power contact lens should be used to correct the vision of a farsighted person whose near point is 80 cm so she can see things clearly that are 25 cm in front of her?
A) -2.8 diopters
B) +4.2 diopters
C) -4.0 diopters
D) +2.8 diopters
E) -4.2 diopters

Question

Quizplus · Accepted Answer

To correct farsightedness, a converging lens with a positive diopter value is needed. Using the lens formula (1/f = 1/v - 1/u), where v is the image distance (25 cm) and u is the object distance (80 cm), the power (P) is calculated as +2.8 diopters.

What Power Contact Lens Should Be Used to Correct the Vision