What is the uncorrected near point of a person who has a near point that is 25 cm from his eyes when he is wearing 3.33-diopter contact lenses?
A) 1.5 m
B) 0.50 m
C) 1.9 m
D) 0.75 m
E) 0.60 m

Question

Quizplus · Accepted Answer

The power of the lens (3.33 diopters) is used to correct the person's vision to a near point of 25 cm. The uncorrected near point can be found using the formula: 1/f = 1/do + 1/di, where f is the focal length of the lens (1/3.33 m), do is the uncorrected near point, and di is the corrected near point (0.25 m). Solving for do gives approximately 1.5 m.

What Is the Uncorrected near Point of a Person Who