A near-sighted person has an eyeball that is 2.65 cm long.What is the effective power of the optical system (combination of lens and cornea)when viewing objects at his near point (18.0 cm)?
A)-37.6 D
B)2.3 D
C)32.2 D
D)37.7 D
E)43.3 D

Question

Quizplus · Accepted Answer

The effective power of the optical system is calculated using the lens formula: 1/f = 1/v - 1/u, where v is the image distance (eyeball length, 2.65 cm) and u is the object distance (near point, 18.0 cm). Converting these to meters and solving gives the power in diopters (D).

A Near-Sighted Person Has an Eyeball That Is 2